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9th Annual CERMM Symposium
May 8 - 10, 2009
Richard J. Renaud Science ComplexConcordia University
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Envisioning the growing importance of computational and theoretical chemistry in modern research, the Concordia Faculty of Arts & Science supported and encouraged the establishment of the Centre for Research in Molecular Modeling (CERMM) in 2000. CERMM is now a multi‐institutional research centre with 23 senior members from 9 institutions with diverse interests. These are exciting times for computational physicists, chemists and biochemists! The Canada Foundation for Innovation is funding Compute Canada along with provincial and industrial partners, a project that will allow Canada to remain at the forefront of computer‐simulation‐based research, and in particular, will provide Québec computational chemists with access to a state‐of‐the‐art computing infrastructure which will be deployed in CERMM as part of the Réseau Québecois de Calcul Haute Performance. The infrastructure available in CERMM has supported in the past the research of over 15 postdoctoral fellows, 50 graduate students and numerous undergraduate students in atmospheric, biological, inorganic, macromolecular, materials, medicinal, organic, physical, and polymer chemistry. The mission of CERMM is to promote excellence in research and graduate education in computational chemistry and biochemistry, to foster collaborations between researchers in different institutions, and to provide an interdisciplinary forum for experimentalists, modelers and theoreticians to combine their expertise to reach new frontiers in the molecular sciences. Accordingly, the CERMM annual symposium is the annual regional event where researchers and students with interests in computational physics, chemistry and biochemistry have the opportunity to showcase their work in the field. This year, we will cut our meeting short and will not have the usual Sunday session because we would not want the CERMM symposium to interfere with Mother’s Day! Also, the Physical, Theoretical and Computational Division of the Canadian Society for Chemistry will offer a $100 award for the best student oral presentation and two $75 awards for best student poster presentations. Finally, I would like to thank the Department of Chemistry and Biochemistry and the sponsors for their generous support, Azuris Technologies in particular for sponsoring the entire Friday reception, my CERMM colleagues and the CERMM students and postdocs for helping organize the symposium. As usual, they did a terrific job! I hope you will all enjoy a fruitful and stimulating symposium.
Gilles H. Peslherbe, CERMM Director
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Friday, May 8, 2009 - Science Pavilion S110, Loyola Campus
17:00 Welcoming remarks: Justin Powlowski, Associate Dean, Arts & Science Discussion Leader: Gilles Peslherbe (Concordia University) Massimo Olivucci (Universitá di Siena and Bowling Green State University) Towards Computational Photobiology 18:15 Reception - Science Pavilion Lower Atrium Hosted by the Department of Chemistry and Biochemistry, Concordia University, and sponsored by Azuris Technologies
Saturday, May 9, 2009 - Science Pavilion S110, Loyola Campus
Discussion Leader: Roger Gaudreault (Cascades Canada Inc.) 9:30 Ajit Thakkar and Sergey Kazachenko (University of New Brunswick) Algorithms for Finding the Global Minima of Molecular Clusters: Application to Water Clusters 10:10 Soran Jarangiri and Gilles Peslherbe (Concordia University) On the Hydration Structure of the Nitrate and Nitrite Ions in Clusters 10:30 Xiaojing Liu and Ian Hamilton (Wilfrid Laurier University) Computational Studies on Gold Clusters, Complexes and Nanostructures 10:50 Coffee Break – Science Complex Lower Atrium Discussion Leader: Matthias Ernzerhof (Université de Montréal) 11:10 Viktor Staroverov (University of Western Ontario) Approximate KohnSham Potentials in Density Functional Theory 11:50 Chun Mak, Qadir Timerghazin and Gilles Peslherbe (Concordia University) Simulations of IodideWater Cluster ExcitedState Dynamics
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12:10 JeanFrancois Truchon (Université de Montréal and Merck Frosst Canada Ltée), Anthony Nicholl's (OpenEye Inc.), Benoit Roux (University of Chicago), Radu Iftimie (Université de Montréal) and Christopher Bayly (Merck Frosst Canada Ltée) Can a Classical Dielectric Continuum Accurately Account for Electronic Polarization? 12:30 Lunch and Poster Session – Science Complex Lower Atrium Discussion Leader: Guillaume Lamoureux (Concordia University) 14:45 Normand Mousseau (Université de Montréal) Simulating Amyloid Formation — Challenges and Progress 15:25 Daniel Oblinsky, Bryan VanSchouwen, Heather Gordon and Stuart Rothstein (Brock University) Do Point Mutations Evoking Disperse Entropic Changes Throughout a Protein Domain? 15:45 Cory Pye (Saint Mary’s University), Raymond Poirier (Memorial University of Newfoundland), D. Jean Burnell (Dalhousie University) and Dieter Klapstein (Saint Francis Xavier University) An Ab Initio Investigation of Cis5,6Disubstituted 1,3Cyclohexadienes 16:05 Coffee Break – Science Complex Lower Atrium Discussion Leader: Monique Laberge (Royal Military College St-Jean) 16:25 Enrico Purisima (Biotechnology Research Institute) Challenges in ProteinLigand Binding Free Energy Calculations 17:05 Feryal Safinejad (Concordia University and Monash University, Australia) Solvent Effects on Static Electric Properties of Carbonyl Compounds 17:20 Qadir Timerghazin (University of Waterloo) and Parisa Ariya (McGill University) Reactions of Bromine Atoms with Alkenes: The Role of Bridged Intermediates 17:45 Presentation of the Student Awards from the Physical, Theoretical and Computational Chemistry Division of the Canadian Society for Chemistry 19:00 Banquet – Restaurant Ilios, 408 Gilford St. (Corner St-Denis)
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1. Development of Transition Metal Reagents for Oxygen Atom Transfer Reactions Mohammad Askari and Xavier Ottenwaelder Concordia University
2. On the Fragmentation of SulfoxideContaining Imidazolium Cations
Mohammad Askari and Gilles Peslherbe Concordia University
3. Molecular Modeling of the Glass Transition in Poly(methyl)methacrylate Bulk and
Thin Films Alexandre Beaudoin, Noureddine Metatla and Armand Soldera Université de Sherbrooke
4. Testing the Weizsacker Kinetic Energy Functional for Pair-Density Functional Theory
Debajit Chakraborty and Paul Ayers McMaster University
5. Thermal Stability of Zeolites: a Computational Investigation
Alexandre Foisy-Geoffroy, Bilkiss Issack and Gilles Peslherbe Concordia University
6. Tests for Functional Derivatives in Density Functional Theory Alex Gaiduk and Viktor Staroverov The University of Western Ontario
7. Improving Reptation Quantum Monte Carlo Robert Giacometti, Wai Kong Yuen, Daniel Oblinsky, and Stuart Rothstein Brock University
8. Effects of Cholesterol on the Solubility of Water inside Lipid Membranes Bilkiss Issack and Gilles Peslherbe Concordia University
9. An Analysis Into The Interactions Between Small MoleculeMetabolites And The Guanine Riboswitch Through The Procurement Of A Stabilization Profile Or “Blue-Print” Petrina Kamya and Heidi Muchall Concordia University
10. Collective Dynamics of Peroxidases Monique Laberge Royal Military College Saint-Jean and Concordia University
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11. Molecular Mechanism of Amyloid Inhibition by Inositol
Grace Li and Régis Pomès University of Toronto and The Hospital for Sick Children
12. Fundamental Interactions between a Palladium precursor and Aromatic Carbons: Theoretical Investigation using First-principles Molecular Dynamics SamirMushrif, 1 Alejandro Rey1 and Gilles Peslherbe2 1McGill University and 2Concordia University
13. An Experimental / Theoretical Coupled Study of the Oxidation of 3- and 5-Formylsalicylic Acids with Potassium Permanganate in Alkaline Medium Esam Orabi, Mostafa Hassan, and Anwar Elshahawy Assiut University (Egypt)
14. Mmotif: A Database Of Metalloenzyme Active Sites Jean-Francois Prieur and Guillaume Lamoureux Concordia University
15. Molecular Conductance In Terms Of Orbital Densities And Polarizabilities Philippe Rocheleau and Matthias Ernzerhof Université de Montréal
16. The Mechanism Of Enzymatic Reactions Of Nucleoside Triphosphate (NTP) Hydrolysis: A Molecular Modeling Investigation Maria Shadrina, 1 Bella Grigorenko, 1 Alexander Nemukhin1,2 1M.V. Lomonosov Moscow State University and 2Russian Academy of Sciences,
17. Ground-State Isomerization of the Green Fluorescent Protein Chromophore Qadir Timerghazin,1Pierre-Nicholas Roy,1 and Alex Brown2
1University of Waterloo and 2University of Alberta
18. A Quantum Chemistry based Force Field for Classical Simulations of High Energy & Density Materials Xijun Wang1 and Huai Sun2
1Concordia University, 2Shanghai Jiatong University;
19. Towards Understanding The Photo-Induced Degradation Of Lignin Lei Zhang, Gilles Peslherbe and Heidi Muchall Concordia University
20. Equiconducting Molecular Electronic Devices Yongxi Zhou, Matthias Ernzerhof Université de Montréal
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Plenary Lecture Friday 17:15
Towards Computational Photobiology
Massimo Olivucci
Universitá di Siena (Italy) and Bowling Green State University, OH (USA) In this lecture, we show how the development of a hybrid quantum mechanics/molecular mechanics computational strategy (see Figure below) based on multiconfigurational perturbation theory and complete-active-space-self-consistent-field geometry optimization has recently allowed for the correct evaluation of the excited-state properties of chemically different chromophores embedded in different protein environments and in solution. In particular, we show how it has been possible to investigate the static and dynamics factors responsible for the color and ultrashort excited state lifetime (see Figure below) observed for rhodopsin proteins (such as rhodopsin and sensory rhodopsins) featuring a cationic retinal chromophore. The same progress in the field of the computational design of artificial bio-mimetic switches will be revised.
1) Structure, Initial Excited-State Relaxation and Energy Storage of Rhodopsin “Resolved” at the CASPT2//CASSCF/AMBER Level of Theory Andruniów, T.;Ferré N. and Olivucci M. Proc. Nat. Acad. Sci.2004, 101, 17908-17913. 2) Excited State Properties of the Green Fluorescent Protein resolved at the CASPT2//CASSCF/CHARMM Level A. Sinicropi, T. Andruniow, N. Ferré, R. Basosi and M. Olivucci J. Am. Chem Soc..2005, 127, 11534-11535. 3) Coto, P.B.; Strambi, A.; Ferré, N.; Olivucci, M.; "The Color of Rhodopsins at the ab initio Multiconfigurational Perturbation Theory Resolution"; Proc. Nat. Acad. Sci. 2006, 103, 17154-17159. 4) The Fluorescence of Tryptophane in Monellin and Parvalbumin Resolved at the ab initio Multiconfigurational Perturbation Theory LevelSinicropi§,A.; Pistolesi§, S.; Pogni, R.; Basosi, R.; Ferré, N. and Olivucci, M. in preparation. 5) Tracking the Excited State Time Evolution of the Visual Pigment with Multiconfigurational Quantum Chemistry Luis Manuel Frutos,Tadeusz Andruniów, Fabrizio Santoro, Nicolas Ferré and Massimo Olivucci Proc. Nat. Acad. Sci.2007, 104, 7764-7769.
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Invited Talk Saturday 9:30
Algorithms For Finding The Global Minima Of Molecular Clusters:
Application To Water Clusters
Ajit Thakkar and Sergey Kazachenko University of New Brunswick
Finding the global minimum of a potential energy surface of a molecular cluster is a difficult problem because the number of minima increases exponentially with respect to the number of atoms in the system. Minima hopping is a recently developed global optimization method which offers several advantages over other popular methods. As a first step this method was implemented in TINKER. To improve performance, rotational and translational perturbations of the monomers were introduced as additional steps in the algorithm. The hydrogen bond topology plays an important role in water clusters, but minima hopping does not always find the best topology. Hence, a hydrogen bond topology optimization algorithm for water clusters was developed. Topology optimization can lower the energy of a cluster by as much as 5 kcal/mol. Minima hopping with the improvements mentioned above was applied to pure water clusters ranging from (H2O)6 to (H2O)37 using the TIP4P force field with subsequent reoptimization of the lowest 2000 structures using the AMOEBA and TTM2.1-F force fields.
Saturday 10:10
On The Hydration Structure Of The Nitrate
And Nitrite Ions In Clusters
Soran Jahangiri and Gilles Peslherbe Concordia University
The hydration structure and thermodynamics of the nitrate and nitrite ions in medium-size water clusters has been investigated by molecular dynamics (MD) simulations and potential of mean force calculations. The self-consistent-charge density-functional tight-binding (SCC-DFTB) model, which is used to describe the intermolecular interactions in the simulations of the NO3
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(H2O)n and NO2-(H2O)n clusters, has been validated against high-level electronic structure
calculations (second-order Møller-Plesset perturbation theory and coupled cluster theory with large basis sets) of the structures and binding energies of small clusters. Results obtained from the SCC-DFTB MD simulations for a cluster containing 12 water molecules show that the nitrate ion, which has a higher polarizability, tends to locate at the surface of the cluster, whereas the nitrite ion, with lower polarizability, preferentially adopts a bulk interior solvation structure.
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Saturday 10:30
Computational Studies On Gold Clusters,
Complexes And Nanostructures
Xiaojing Liu and Ian Hamilton Wilfrid Laurier University
Gold clusters have unique properties that depend strongly on cluster size but, to utilize these in the liquid phase, it is necessary to prevent coalescence. In colloidal solution, sulphur ligands are often used as surfactants, due to the strength of the Au-S bond. We have characterized bare gold clusters, Aun, their complexes with hydrogen sulphide, AunSH2, and internal proton transfer to form HAunSH. We have examined many-body energies for small gold clusters and found that they are large. It is therefore not surprising that gold nanoclusters can exhibit unusual long-range order. We have shown that bare gold nanoclusters with 24 to 40 gold atoms can exhibit helicity, as illustrated for Au24. These are not the minimum energy structures but they are stable and robust. Their unusual properties are currently being investigated.
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Invited Talk Saturday 11:10
Approximate Kohn-Sham Potentials in Density Functional Theory
Viktor Staroverov
Université de Montréal Most developments in Kohn‐Sham density functional theory focus on density functional approximations while Kohn‐Sham potentials are given a supporting role. In this talk, we will outline an alternative approach in which the Kohn‐Sham potential is brought to the fore and approximated directly while the energy is extracted from the potential. It turns our that, given a Kohn‐Sham exchange‐correlation potential in analytical form, it is easy to reconstruct the parent density functional up to a gauge transformation of the energy density. The potential‐first approach has several advantages but also presents new theoretical challenges. Numerical calculations involving actual model potentials are presented and the pros and cons of the inverted Kohn‐Sham scheme are discussed.
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Saturday 11:50
Simulations of Iodide-Water Cluster Excited-State Dynamics
Chun Mak, Qadir Timerghazin and Gilles Peslherbe
Concordia University
Photoexcitation of aqueous iodide solutions results in the generation of solvated electrons, which are involved in such diverse processes as the radiation induced damage of living cells, organic reduction reactions, and the detoxification of chemical weapons. Similarly, photoexcitation of iodide-water clusters [I-(H2O)n, n>2]results in the transfer of an electron from the iodide to the water cluster moiety. Time-resolved femtosecond photoelectron spectroscopy measurements of photoexcited I-(H2O)n have revealed complex relaxation dynamics after excitation, which lead to a gradual increase in the stability of the excited electron. In order to gain an in depth understanding of the molecular mechanisms of electron stabilization in photoexcited I-(H2O)n, excited-state ab initio molecular dynamics simulations of the relaxation dynamics are performed. Preliminary simulation results suggest that after excitation, the iodide-water clusters rearrange from the initial Franck-Condon geometries to structures with a higher dipole moment, which bind the excess electron more strongly. Furthermore, the observed relaxation dynamics were found to have a strong dependence on the initial structure and kinetic energy of the clusters. These initial results support the “solvent-driven” model of excited I-
(H2O)n relaxation dynamics, though the effect of the iodine atom cannot be ruled out. Results of these simulations also offer a glimpse at the fascinating molecular details behind the process of electron solvation in polar macroscopic liquids.
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Saturday 12:10
Can a Classic Dielectric Continuum Accurately Account
for Electronic Polarization?
Jean-François Truchon1,2, Anthony Nicholl’s3, Benoit Roux4, Radu Iftimie1 and Christopher Bayly2
1Université de Montréal, 2Merck Frosst Ltée, 3Open Eye Inc., 4University of Chicago
We report that a simple Dielectric model can be used to accurately account for electronic polarization. The generalization of EPIC (Electronic Polarization from the Internal Continuum) to a wide range of bioorganic chemistry makes the model appropriate for biomolecular force field applications where polarizability matters. The use of Poisson's electrostatic theory to represent the polarization makes this model also appropriate to easily includes solute polarizability in continuum solvent models.
Invited Talk Saturday 14:45
Simulating Amyloid Formation — Challenges and Progress
Normand Mousseau
Université de Montréal Insoluble amyloid fibrils are associated with a number of degenerative diseases such as Alzheimer's, Parkinson's and Huntington's diseases. While the exact structure of these assemblies is still unknown, it has become clear, in the last decade, that small soluble intermediate structures are much more toxic than the fully fibrils. Because of the inherent kinetic dynamical nature of these small aggregates, however, it has been very difficult to obtain clear experimental results and computer simulations have emerged as an essential tool in the study of the onset of amyloid formation. In this talk, I'll discuss the state of the art in simulating these systems, with an emphasis on the results obtained by our group. The work reported here was done in collaboration with Rozita Laghaei and Jessica Nasica (Université de Montréal), Philippe Derreumaux (Institut de biologie-physico chimique, Paris), and Guanghong Wei (Fudan University, Shanghai).
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Saturday 15:25
Do Point Mutations Evoking Disperse Entropic Changes Throughout A
Protein Domain?
Daniel Oblinsky, Bryan VanSchouwen, Heather Gordon and Stuart Rothstein Brock University
Protein G B1 exhibits remarkable thermal stability. Its thermal stability changes, sometimes dramatically upon mutations at position 53. There is known to be a strong entropic component to its structural stability. Experimental efforts to explain this based on local perturbations, such as solvent interactions and steric effects have failed. We performed MD simulations on WT B1 domain and selected mutants to explain trends in thermal stability as a function of mutation. We find that entropy of backbone motion, a component of peptide stability of the mutants, is dispersed throughout the backbone, and increases with the goodness of fit of their Procrustes rotated principle components to WT B1 domain.
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Saturday 15:45
An Ab Initio Investigation Of Cis-5,6-Disubstituted 1,3-Cyclohexadienes
Cory Pye,1 Raymond Poirier,2 D. Jean Burnell,3 Dieter Klapstein4
1Saint Mary's University, 2Memorial University of Newfoundland, 3Dalhousie University, 4Saint Francis Xavier University
A computational study of 1,3-cyclohexadiene and some 5,6-substituted derivatives is presented. We examine the barrier to inversion of 1,3-cyclohexadiene itself, followed by various derivatives such as the alcohol, diol, dimethoxy, and a series of cyclic diol derivatives. The barrier to ring inversion correlated with the reported rate of Diels-Alder reaction, but not to the syn-anti ratio. Analysis of the photoelectron spectrum of the dienes offers no insight towards understanding the syn/anti ratio. The transition structures to Diels-Alder reaction are similar for the reaction of 1,3-cyclohexadiene with both ethene and ethyne.
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Invited Talk Saturday 16:25
The Entropic Term in Protein-Ligand Binding Free Energy Calculations
Enrico Purisima
Biotechnology Research Institute, National Research Council Canada The rational design of high-affinity inhibitors/ligands is hampered by the complex interplay between enthalpy and entropy. Indeed, through a phenomenon known as enthalpy-entropy compensation, chemical modifications designed to provide additional enthalpic interactions often do not yield the expected enhanced binding affinities due to compensating changes in entropic cost. While free energy perturbation calculations offer a rigorous way to calculate free energies of binding, the prohibitive expense of these calculations leave a clear need for higher-throughput methods to approximate these quantities. In this talk, we will explore the issue of entropy and describe a method for calculating binding free energies using a direct build-up of the partition function.
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Saturday 17:05
Solvent Effects On Static Electric Properties Of Carbonyl Compounds
Feryal Safinejad Concordia University and Monash University (Australia)
Nonlinear optical materials have great impact on information technology; these materials can be used for data storage, optical information processing, and telecommunication. Determination of polarizability and hyperpolarizability of molecules can provide valuable information regarding the linear and nonlinear optical properties of materials. Dipole moments (), polarizabilities () and first order hyperpolarizabilities () of several carbonyl compounds have been studied using ab initio and density functional theory (DFT). The Onsager reaction field and polarized continuum model (PCM) have been emplyed to investigate solvent effects on the nonlinear optical properties of the molecules studied.
Phthalic acid Succinimide N-chlorophthalimide While in general there is a reasonable agreement with experiment, the choice of the basis set and/or the theoretical method has a noticeable effect on the calculated quantities. The calculated electric properties from the two reaction field models are in reasonable agreement although the polarized continuum model shows larger solvent effects. Studying harmonic vibrational frequencies by the Onsager and PCM procedures, on the other hand, may lead to contradictory outcomes. For 1,2-benzenedicarboxylic anhydride (phthalic anhydride), the Onsager model predicts a blue-shifted C–H stretching band, whereas PCM leads to a red-shifted C–H stretching mode [1]. 1) F. Safinejad, C. Thompson, M. Asghari-Khiavi, J. Mol.Model. doi:10.1007/s00894-009-0462-9
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Saturday 17:20
Reactions of Bromine Atoms with Alkenes:
The Role of Bridged Intermediates
Qadir Timerghazin1 and Parisa Ariya2 1University of Waterloo, 2McGill University
Existence and the nature of the bridged halogen atom‐alkene adducts have been a matter of a considerable debate for a few decades. In this contribution, we will present high‐level multi‐reference CASPT2, MRCI+Q as well as DFT calculations of the various forms of bromine atom adducts with ethene and tetrachloroethene. We will demonstrate that the single‐reference post‐Hartree‐Fock calculations tend to greatly overestimate the stability of the bridged structures. The role of the spin‐orbit coupling effects on the stability of the bridged Br‐alkene adducts will also be discussed in detail. The insights gained from the computational investigation will be used to rationalize the experimentally observed kinetics of the atmospherically relevant bromine‐alkene reactions.
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Poster 1
Development of Transition Metal Reagents
for Oxygen Atom Transfer Reactions
Mohammad Askari and Xavier Ottenwaelder* Concordia University
Inspired by the outstanding oxidative reactivity of metalloenzymes and in search of strong and efficient oxygen atom transfer reagents for the synthesis of fine chemicals, we are investigating the synthesis of compounds containing a metalloxaziridine ring. We have prepared molybdenum-imido complexes capable of receiving an oxygen atom and studied their reactivity towards oxidizing agents, which yielded in the formation of a structurally unusual molybdenum dimer. Computational investigations using the B3LYP functional and double-ζ basis sets revealed the formation of two intermediates upon the reaction of the molybdenum-imido complex with an oxygen atom. Based on the electronic structures of the intermediates we hereby propose a mechanism for the formation of the dimer which accounts for the experimentally observed product.
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Poster 2
On the Fragmentation of SulfoxideContaining Imidazolium Cations
Mohammad Askari and Gilles Peslherbe
Concordia University Ionic liquids of sulfoxide‐containing imidazolium cations constitute an important class of environment‐friendly solvents, used for instance for the Swern oxidation1. Mass spectra of the cations have been found to be very sensitive to the chain length of the alkyl group and the oxidation state of the sulfur atom2. To account for the fragments observed in the mass spectra, density‐functional theory calculations were performed on model compound 1 with the PBE0/6‐31+G* model chemistry. Characterization of the intermediates and transition states revealed the presence of two competing pathways which could account for all the observed fragments in the experimental mass spectrum. The results of preliminary dynamical simulations of surface‐induced fragmentation will also be presented. Fragmentation pathways are found to depend on the initial relative collision energy.
N N S
O 1
1 Xun He and Chan T.H., Tetrahedron 2006; 62: 3389 2 Lesimple A. et al., J. Mass. Spectrom. 2008; 43: 35–41
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Poster 3
Molecular Modeling of the Glass Transition in Poly(methyl)methacrylate Bulk and Thin Films
Alexandre Beaudoin, Noureddine Metatla and Armand Soldera
Université de Sherbrooke
The glass transition (Tg) remains one of great nature’s mysteries and a major controversy in the polymer science field. To this day, no single theoy exists that can explain this phenomenom entirely. Many factors affect the value of Tg such as polymer rigidity, interactions, tacticity and the thickness of the polymer film. From an atomistic simulation viewpoint, it has been shown that tacticity can be accurately reproduced. Moreover, following a specific procedure, simulated Tgs are revealed to be correlated to experimental data through the established WLF relation. The purpose of this presentation is first to expose this correlation, and then to apply our procedure to investigate the variation in Tg experimentally observed for a polymer film comparatively to the bulk. For that purpose, poly(methyl)methacrylate (PMMA) is chosen since it offers a special regard to the study of the glass transition: according to the tacticity of its chain, a different value of Tg is exhibited. As a matter of fact, an accurately simulated difference in Tgs stems from a variation in molecular characteristics only. By revealing these differences at the atomistic level, molecular modeling offers an additional asset in gaining insight into the perplexing problem of the glass transition phenomenon. However, domains of time and length covered by atomistic simulation are far too small in comparison with experiments. Consequently, an accurate representation of the phase space has to be undertaken, and an intimate comparison with theory and experimental data is crucial. After revealing the adequacy of the proposed procedure to take into account the statistical nature of the polymer chain, this poster intends to show the agreement between simulated and experimental Tgs. Preliminary results on simulated isotactic PMMA thin films are exposed : they actually show an expected decrease in Tg. Hints on the atomistic nature of this phenomena can thus be provided.
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Poster 4
Testing the Weizsacker Kinetic Energy Functional For Pair-Density Functional Theory
Debajit Chakraborty and Paul Ayers
McMaster University
In pair-density functional theory and other density functional theories based on higher-order electron distribution functions, the electron-electron repulsion energy can be computed exactly, and so the only portion of the energy that needs to be approximated is the kinetic energy. Finding accurate approximate kinetic energy functionals for k-density functional theory seems very challenging. The simplest functional that have been proposed are probably the generalized Weizsackerforms; it has been speculated in the literature that the generalized Weizsacker form might be accurate, but our calculations, atoms in the second row of the periodic table and some isoelectric series in groups II and III, suggest that the Weizsacker functional is not accurate. In accord with theoretical results, the Weizsacker Functional is a lower bound to the true kinetic energy, but the quality of the functionals rapidly deteriorates as the number of electrons increases. This motivates work on new forms of approximate kinetic energy functionals.
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Poster 5
Thermal Stability of Zeolites: a Computational Investigation
Alexandre Foisy-Geoffroy, Bilkiss B. Issack and Gilles H. Peslherbe Concordia University
Zeolites are microporous materials, usually aluminosilicates, known for their ability to act as molecular sieves and catalyze reactions based on size selectivity. They play an important role in catalysis, notably the catalytic cracking of petroleum crude oils to gasoline and other fuels at high temperatures. While experimental studies of the thermal stability of zeolites are legion, very few computational studies have been reported. In this contribution, we will discuss a computational method to measure two properties of zeolites that are directly related to their thermal stability: the crystalline character and the pore size. The method has been validated for silicalite, the all-silica version of the ZSM-5 zeolite, with the Catlow/Faux Force Field1,2
1) R. A. Jackson; C. R. A. Catlow; "Computer Simulation Studies of Zeolite Structure", Mol. Sim. 1 207-224 (1988) 2) D. A. Faux, W. Smith; T. R. Forester; "Molecular Dynamics Studies of Hydrated and Dehydrated Na+-Zeolite-4A", J. Phys. Chem. B 101 1762-1768 (1997)]
Poster 6
Tests for Functional Derivatives in Density Functional Theory
Alex Gaiduk and Viktor Staroverov The University of Western Ontario
We use three practical tests for determining whether a given exchange-correlation potential is not a functional derivative: (i) oscillatory behavior of the self-consistent-field procedure; (ii) path dependence of the van Leeuwen‒Baerends line integral; (iii) certain translational and rotational symmetry properties of the potential. The tests are applied to several model potentials proposed recently in the literature. It turns out that none of them is a functional derivative. This implies that energies assigned to these model potentials are not unique and, therefore, should be interpreted with caution.
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Poster 7
Improving Reptation Quantum Monte Carlo
Robert Giacometti, Wai Kong Yuen, Daniel Oblinsky, and Stuart Rothstein
Brock University The reptation quantum Monte Carlo (RQMC) algorithm proposed by Baroni and Moroni1 is a promising development that has been used to elucidate electronic structures and other ground-state properties of quantum systems. In this approach, one generates a large number of aptly named reptiles, each containing sets of electron configurations arising from consecutive drift-diffusion moves within the system being studied. Within the fixed-node approximation, one may extract estimates of the exact energy from the reptiles' heads and tails (their first and last configurations of electrons, respectively), and estimate expectation values for operators that do not commute with the Hamiltonian from their middle configurations. This approach is advantageous over conceptually equivalent algorithms as each estimate is free from population control bias. Unfortunately, the time-step bias may accumulate and adversely affect the accuracy associated with estimates of the physical properties of atoms and molecules.2 For this purpose we propose an alternative algorithm, head-tail adjusted reptation quantum Monte Carlo, engineered to remedy this deficiency, while still simulating the target distribution for RQMC. The effectiveness of our approach is demonstrated by an application to ground-state LiH. We estimate the fixed-node energy with improved reliability, without adversely affecting the quality of estimates of other, non-energy-related properties. References: 1) Baroni, S.; Moroni, S. Phys. Rev. Lett.1999, 82, 4745. 2) Coles, B.; Vrbik, P.; Giacometti, R.D.; Rothstein, S.M. J. Phys. Chem. A 2008, 112, 2012.
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Poster 8
Effects of Cholesterol on the Solubility of Water inside Lipid Membranes
Bilkiss Issack and Gilles Peslherbe Concordia University
The cell membrane is responsible for controlling the passage of molecules into and out of cells. As an integral part of the membrane living human cells, cholesterol can be found in widely differing concentration, ranging from a few molecules to nearly half of the lipid content of the membrane. The cholesterol content is known to modulate the physical properties of membranes such as their flexibility and fluidity, [Needham et al., 1988] consequently affecting the passive transport of small molecules. [Subczynski et al. (1994)] The processes by which cholesterol alters the solubility and passage of molecules into the membrane interior are, however, still unclear. The present work aims at investigating the effects of cholesterol on the thermodynamics of water transport across lipid membranes. Atomistic molecular dynamics simulations are carried out on model lipid membranes containing cholesterol at different concentrations with the GROMACS software package. Free energy profiles are calculated and compared in order to determine the role of cholesterol in the membrane solubility of water.
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Poster 9
An Analysis Into The Interactions Between Small Molecule Metabolites And
The Guanine Riboswitch Through The Procurement Of A Stabilization Profile Or “Blue-Print”
Petrina Kamya and Heidi Muchall
Concordia University Riboswitches regulate the expression of genes through the formation of selective interactions between very specific metabolites that bind the mRNA in the aptamer region of the sequence. Using experimentally determined crystal structures of these small metabolites bound to the “active site” we show here that through the isolation of the metabolite when bound to the important bases in the binding site and the use of the quantum theory of atoms in molecules to analyze the electron density distribution of the wavefunction of this model system, one can unequivocally identify and quantify the stabilizing interactions occurring between the bases in the active site and the bound metabolites. This work shows that a molecular graph of an active site bound to its substrate provides a “blue print” of the stabilizing interactions that can be used in the design and development of highly specific agonists or antagonists for the target molecule which in this case is the guanine riboswitch.
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Poster 10
Collective Dynamics of Peroxidases
Monique Laberge1,2 1Royal Military College Saint-Jean, 2Concordia University
Abstract: Cass III peroxidases have structures stabilised by the presence of two endogenous calcium atoms. The role of calcium as a regulator of protein conformational dynamics was investigated by performing 20-ns molecular dynamics simulations on explicitly solvated horseradish peroxidase and Ca-depleted models. Cross-correlation analysis is a powerful tool that can identify the correlated motions perturbed in the absence of calcium. Complemented by an essential dynamics analysis, the conformational space sampled by the peroxidases can be effectively sampled. Principal components analysis was used to decompose the covariance matrix extracted from the simulations and reconstruct the trajectories along the principal coordinates representative of functionally important collective motions. The results show that the motion of the native species is defined by a few preferred directions identified by the first four eigenvectors. The eigenvectors are significantly sampled, suggesting that, on average, large motions involving different subdomains of the protein occur. The analysis reveals that the calcium depletion affects the most important components of the hrpc motions and modify the overall dynamics in regions where functionally significant residues are located -notably in the heme pocket. Funding from NSERC grant 9988-06 and FQRNT 2010-PR-133873 is acknowledged.
30
Poster 11
Molecular Mechanism of Amyloid Inhibition by Inositol
Grace Li and Régis Pomès
University of Toronto and The Hospital for Sick Children Alzheimer's Disease is a severe neurodegenerative disease linked with the extracellular deposition of Aβ42 amyloid. A recently discovered potential therapeutic for the treatment of AD, scyllo-inositol, is currently in phase II of clinical trials. However, the mechanism of action of inositol at the molecular level is not known. We have performed extensive molecular dynamics simulations of scyllo-inositol and its inactive stereoisomer, chiro-inositol, with amyloidogenic peptides (GA)4 and KLVFFAE to systematically characterize both the binding and the effect of inositol on the structure and morphology of species in the amyloid aggregation pathway. Our results suggest that scyllo-inositol does not act as a drug on aggregates of (GA)4. In particular, both isomers bind nonspecifically to the peptidic backbone of (GA)4 with low affinity and do not significantly affect the morphology of aggregates. However, our preliminary results from simulations with aggregates of KLVFFAE show that inositol have sequence dependent binding modes and can interact significantly with sidechains of phenylalanine, lysine, and glutamate.
31
Poster 12
Fundamental Interactions between a Palladium precursor and Aromatic Carbons: Theoretical Investigation using First-principles Molecular
Dynamics
Samir Mushrif,1 Alejandro Rey1 and Gilles Peslherbe2
1McGill University, 2Concordia University
The interaction between palladium precursors and polyaromatic carbon materials is of fundamental importance to synthesis of carbon supported palladium catalysts used in catalytic hydrogenation and combustion and in catalytic growth of carbon nanostructures and to the synthesis of palladium doped carbon fibers for hydrogen storage. Though experimental studies suggest that the palladium precursor decomposes in the presence of aromatic carbon and that the carbon structure gets chemically modified in the presence of palladium precursor, a molecular level understanding is lacking. We perform first principles molecular dynamics simulations of chrysene, a model polyaromatic carbon compound, and palladium (II) acetylacetonate, a common palladium complex used as palladium precursor. Validating and augmenting the experimental studies, our simulation results show that (i) the acetylacetonate ligand-carbon interaction leads a way to decompose palladium (II) acetylacetonate and that this ligand-carbon interaction induces covalent cross-linking in the neighboring aromatic carbons. Using the electron localization function analysis, we also divulge partial reduction of palladium and its interaction with the carbon.
32
Poster 13
An experimental / theoretical coupled study of the oxidation of 3- and 5-formylsalicylic acids with potassium permanganate in alkaline medium
Esam Orabi, Mostafa Hassan, and Anwar Elshahawy
Concordia University
The kinetic of oxidation of two aromatic aldehydes, 3-formylsalicylic acid (3fsa) and 5-formylsalicylic acid (5fsa), has been studied. An energetically based comparison between different possible structures of 3fsa and 5fsa in their molecular, unicharged and dicharged states has been performed by applying the DFT through B3LYP/6-31G** basis set. Comparing the ionization energies and electron affinities of the most stable structures indicated that oxidation of 5fsa is easier than 3fsa. The activation energies of the two reactions have been determined confirming the theoretical expectation. The reaction has been found to pass through formation of a spectrophotometrically detectable Mn(V) and Mn(VI) transient species. A mechanism of the reaction is suggested.
Poster 14
Mmotif: A Database Of Metalloenzyme Active Sites
Jean-Francois Prieur and Guillaume Lamoureux Concordia University
Metalloenzymes are catalytic proteins that function in the presence of a metal cofactor such as zinc, magnesium or iron. They are involved in numerous fundamental biological processes and are important therapeutic targets against cancer, hypertension and bacterial infections. They also have considerable industrial potential as biocatalysts. We are constructing a database of metalloenzyme active sites, calledmmotif, that organizes the large amount of structural information on enzymes according to the architecture of their active sites. The database is built on Protein Data Bank, and contains (1) annotated structures of all metalloenzyme active sites (to be used in comparative studies across protein families), and (2) gas-phase models of the metal-binding sitesthat can be used for further analysis using ab initioor DFT calculations. This information will allow us to answer many questions related to the structure and function of enzymes, such as: What range of functions has a given metal-binding motif? Can a given active site motif be supported by different protein folds? How metal-specific (or substrate-specific) is a given motif?
33
Poster 15
Molecular Conductance In Terms Of Orbital Densities
And Polarizabilities
Philippe Rocheleau and Matthias Ernzerhof Université de Montréal
In molecular electronics, molecules are connected to macroscopic contacts. In our work we focus on modeling the transmission of electrons through a molecular electronic device (MED). We use conventional perturbation theory (where the contacts are represented by a perturbing potential1) to calculate the transmission probability T(E) for an electron to pass through the molecule. This allows us to express T(E) in terms of properties of the bare molecule. We show that, in general, it is the electron density (first-order contribution) on the atoms that connect to the contacts that contributes the most to the transmission probability of the MED. The second-order correction, determined by the orbital polarizability, adds little improvement on the first-order results for the system studied. Using this approach, we obtain a simple qualitative answer to the question why the molecule studied by M. Mayor2 shows orders of magnitude difference in the conductance by changing the contact attachment points in the molecule. We outline an extension of our method that accounts for correlation effects. 1) F. Goyer, M. Ernzerhof and M. Zhuang, J. Chem. Phys., 126, (2007) 144104 2) M. Mayor et al., Angewandte Chemie Int. Ed., 42, (2003) 5834
34
Poster 16
The Mechanism Of Enzymatic Reactions Of Nucleoside Triphosphate (NTP)
Hydrolysis: A Molecular Modeling Investigation
Maria Shadrina,1 Bella Grigorenko,1 Alexander Nemukhin1,2 1Moscow State University, 2Russian Academy of Sciences
This work is devoted to the studies of nucleoside triphosphates (NTP) hydrolysis reactions in different biochemical systems. Chemical reactions of NTP hydrolysis lead to nucleoside diphosphate (NDP) and inorganic phosphate (Pi), NTP + H2O → NDP + Pi , and constitute the most important and widespread enzymatic processes in biology. We use an approach to the hybrid quantum mechanical and molecular mechanical (QM/MM) theory based on the effective fragment potential (EFP) technique for modeling properties and reactivity of large molecular systems of biochemical significance. This method allows us to model mechanisms in biochemical systems taking into account the protein environment. The entire system under consideration is divided into QM and MM parts. The QM part includes atoms participating in the reaction. The ММ part includes surrounding protein chains. Energies and forces are computed by classical equations. This general strategy has provided detailed insight into the mechanisms of these reactions, and has allowed us to infirm common features for various biochemical systems. We have found the mechanisms of hydrolysis of methyl triphosphate (MTP) in water, adenosine triphosphate (ATP) by myosin, guanosine triphosphate (GTP) by human protein p21Ras (alone and complexed with the activating protein GAP), and by EF-Tu (alone and complexed with ribosome). It was shown that in all cases the hydrolysis proceeds through a low-barrier cleavage of the Pγ-Oβγ bond of nucleoside triphosphate, then separation of the metaphosphate moiety PO3- with a subsequent stage of proton transfers to complete the formation of inorganic phosphate. We have found a unique hydrogen bonding net work in active sites of the studied proteins. Enzyme-substrate complexes for main types of active sites of G-proteins were also constructed. It was shown that such a hydrogen bonding net work is conserved for NTP-hydrolysing proteins and promotes the hydrolysis reactions of NTP. Consequently, we consider that hydrolysis reactions of NTP in different systems follow the same dissociative mechanism.
35
Poster 17
Ground-State Isomerization of the
Green Fluorescent Protein Chromophore
Qadir Timerghazin,1 Pierre-Nicholas Roy,1 and Alex Brown2
1University of Waterloo, 2University of Alberta Green fluorescent protein (GFP) and other homologue fluorescent proteins (FPs) are widely used as markers in molecular and cellular biology. A number of FPs demonstrate photoswitching behaviour related to photoconversion of the chromophore from the fluorescent Z isomer to the non-fluorescent E isomer. This photobleaching process may be reversed by irradiation at a different (shorter) wavelength or thermally. Although the reversible photobleaching can be detrimental to the application of FPs as fluorescent probes, it may also lead to applications in photoswitching devices. Photoswitching of the FPs is a complex process involving the isomerization of the chromophore itself, and the rearrangement of the aminoacid residues around it. In this contribution, we will describe our approache to the theoretical study of the Z-E isomeriazation of the GFP chromophore on the ground-state potential energy surface. Ab initio and DFT electronic structure calculations as well as the molecular dynamics simulations will be presented and the calculated free energy profiles will be used to discuss the possible mechanisms of the thermal fluorescence recovery in the phtobleached FPs.
36
Poster 18
A Quantum Chemistry based Force Field for Classical Simulations of High Energy & Density Materials
Xijun Wang1 and Huai Sun2
1Concordia University, 2Shanghai Jiatong University
Several nitro-amine compounds, such as HMX, TNAZ, CL20, TATB etc, named high energy density materials (HEDM), have important applications in the space industry After being triggered, self-sustainable detonating reactions of these kinds of solid organic crystal materials would release a great deal of gas and energy. Prime interest lies in understanding the mechanism of initial detonation, design and synthesis of new HEDM species with low sensitivity. Experimental studies of such materials are expensive, dangerous and environmental unfriendly. Classical simulations can provide data for the equation-of-state of HEDM in extreme states. But few general force fields for solid materials like CFF or COMPASS were optimized for these nitro-amine compounds. In this work, a quantum chemistry based force field was developed and validated for classical simulations of these materials. The protocol of parameterization is tested to be accurate and could be used to supplement missing parameters for other similar systems. The force field then was used to predict the equation-of-state data and the lattice parameters of polymorphs. The results are in good agreement with available experimental measurements.
37
Poster 19
Towards Understanding the Photo-Induced Degradation Of Lignin
Lei Zhang, Gilles Peslherbe and Heidi Muchall Concordia University
It is well known that phenoxyl radicals may be produced during the photo-oxidation of lignin. These radicals may be further oxidized to produce quinones, which are believed to be responsible for the photo-induced yellowing of lignin-rich, high-yield, mechanical pulps. To date, three main mechanisms for the formation of phenoxyl radicals have been identified, the phenol, phenacyl and ketyl pathways.1-3Although the ketyl pathway (which involves molecular oxygen) is expected to be important, its role in the photo-yellowing of lignin containing pulps and papers is still under debate. In this contribution, we will report the results of exploratory calculations of possible reactions of the singlet and triplet excited states of simple model systems, such as acetone, sulfoxides and dibenzodixocins shown below.
(1) Schmidt, J. A.; Heitner, C. Journal of Wood Chemistry and Technology1993, 13, 309-
325. (2) Leary, G. J. Journal of Pulp and Paper Science1994, 20, 154-160. (3) Shukla, D.; Schepp, N. P.; Mathivanan, N.; Johnston, L. J. Canadian Journal of
Chemistry1997, 75, 1820-1829.
38
Poster 20
Equiconducting Molecular Electronic Devices
Yongxi Zhou and Matthias Ernzerhof Université de Montréal
For molecular conductors, the SSP Huckel model [1,2] provides a simple tool for the calculation of the electron transmission probability. Recently, [3] the SSP method has been combined with graph theory and criteria have been established under which two different molecular electronic devices yield identical transmission probabilities. Since these criteria have been arrived at within the Huckel approximation, here we investigate the validity of these criteria by performing Kohn-Sham density functional calculations combined with a Green's function approach for the transmission probability. We find that some systems, predicted to be equiconducting, remain equiconducting at the ab-initio level while others do not. Explanations for the obtained discrepancies are provided. 1) F. Goyer, M. Ernzerhof, M. Zhuang, J. Chem. Phys. 126 (2007) 144104 2) M. Ernzerhof, J. Chem. Phys. 127 (2007) 204709 3) P. W. Fowler, B. T. Pickup, T. Z. Todorova, Chem. Phys. Lett. 465 (2008) 142
39
Poster 21
Towards Understanding the Dissociation Mechanism of a Weak Acid in Aqueous Solution
Vibin Thomas and Radu Iftimie
Université de Montréal
Understanding the dissociation mechanism of a weak acid in aqueous solution is of great importance not only for acid-base chemistry but also for understanding many biological processes. A detailed microscopic mechanism for weak acid dissociation in solution can only be obtained by finding and characterizing the intermediates of dissociation. As an important first step, we successfully explored the ability of hydrofluoric acid to produce dissociation intermediates using carefully designed first principles molecular dynamics simulations and characterize them using infrared spectroscopy by spectral decomposition technique based on maximally localized wannier orbitals. This is achieved by investigating the various compositions of amorphous mixtures of hydrogen fluoride and water at cryogenic conditions, favoring the formation of ion-pair dissociation intermediates to reach following conclusions. First, The broad “continuous” IR absorption ranging from 1000 to 3000 cm-1 shown by the cryogenic mixtures of HF and H2O are due to the presence of proton shared and ion-pair dissociation intermediates. The proton shared species are responsible for the intense absorption centered at 1800cm-1. Second, topology of first solvation shell determines the ionization and the asymmetric stretching frequency of shared proton of H2O.HF complex. Third, we are able to propose a mechanism of ionization by linking the first solvation shell pattern and degree of ionization. Fourth,A comparatively smaller magnitude of Nuclear quantum effects observed in this case shows that the local potential felt by hydrogen atoms in amorphous-phase proton-shared ion pairs is quasi-harmonic. Fifth, The shape of proton potentials for the three limiting structures are similar. Sixth, Long range electro static effects are small compared to the first solvation shell effect in determines the fate of ion-pair intermediates 1.Radu Iftimie, Vibin Thomas et al. Journal of the American Chemical Society 2008 130 (18), 5901 2.Vibin Thomas and Radu Iftimie. Journal of Physical Chemistry B 2009 113 (13), 4152
40
Ajit Thakkar University of New Brunswick ajit@unb.ca
Alex Gaiduk The University of Western Ontario
agaiduk@uwo.ca
Alexandre Beaudoin Université de Sherbrooke alexandre.beaudoin@usherbrooke.ca
Alexandre Foisy-Geoffroy Concordia University, alexandre@cermm.concordia.ca
Alexandre Meunier Merck Frosst Canada Ltée jeanfrancois_truchon@merck.com
Bilkiss Issack Concordia University bbissack@alcor.concordia.ca
Chun Mak Concordia University Chun.Mak@cermm.concordia.ca
Cory Pye Saint Mary's University cory.pye@smu.ca
Danny Sichel Cité des Sciences et de l'Industrie
dsichel@gmail.com
Debajit Chakraborty McMaster University chakrd2@mcmaster.ca
Denise Koch Concordia University management@cermm.concordia.ca
Ann English Concordia University english@alcor.concordia.ca
Enrico Purisima Biotechnology Research Institute Enrico.Purisima@cnrc-nrc.gc.ca
Esam A. Orabi Concordia University esam_oraby2001@yahoo.com
Feryal Safinejad Concordia University fsafinejad@gmail.com
Francois David Concordia University fg_david@live.concordia.ca
Gilles Peslherbe Concordia University Gilles.Peslherbe@CERMM.Concordia.CA
Grace Li University of Toronto grace.li@utoronto.ca
Guillaume Lamoureux Concordia University glamoure@alcor.concordia.ca
Heidi Muchall Concordia University muchall@alcor.concordia.ca
Ian Hamilton Wilfrid Laurier University ihamilton@wlu.ca
Ilya Ryabinkin The University of Western Ontario
igryabinkin@gmail.com
Jean Francois Prieur Concordia University jfprieur@gmail.com
Jean-Francois Truchon Merck Frosst Canada Ltée jeanfrancois_truchon@merck.com
41
Lei Zhang Concordia University lei@cermm.concordia.ca
Maria Shadrina M.V. Lomonosov Moscow State University
Maria@cermm.concordia.ca
Massimo Olivucci Universitá di Siena (Italy) and molivuc@bgnet.bgsu.edu Bowling Green State University
Matthias Ernzerhof Department of Chemistry, University of Montreal
matthias.ernzerhof@umontreal.ca
Mohammad. Askari Concordia University ms.askari@gmail.com
Monique Laberge Royal Military College St-Jean and Concordia University
M.Laberge@st-jean.rmc.ca
Normand Mousseau Université de Montréal normand.mousseau@umontreal.ca
Petrina Kamya Concordia University petrin@cermm.concordia.ca
Philippe Rocheleau Universite de Montreal philippe.rocheleau@umontreal.ca
Qadir Timerghazin University of Waterloo qadirt@uwaterloo.ca
Randy Dumont McMaster University dumontr@mcmaster.ca
Robert Giacometti Brock University rg05vx@brocku.ca
Rogelio Cuevas McMaster University cuevasr@mcmaster.ca
Roger Gaudreault Cascades Canada Inc. rgaudreault@cascades.com
Samir Mushrif McGill University samir.mushrif@mail.mcgill.ca
Soran Jahangiri Concordia University soran@cermm.concordia.ca
Stuart Rothstein Brock University srothste@brocku.ca
Vibin Thomas University of Montreal vibinipe@gmail.com
Viktor Staroverov University of Western Ontario vstarove@uwo.ca
Wang, Xijun Concordia University xijunw@gmail.com
Yongxi Zhou Université de Montréal quangeez@gmail.com
42
Parisa Ariya, Departments of Chemistry and Atmospheric & Oceanic Sciences, McGill University
Scott Bohle, Department of Chemistry, McGill University
Louis Cuccia, Department of Chemistry & Biochemistry, Concordia University
Christine DeWolf, Department of Chemistry & Biochemistry, Concordia University
Ann English, Department of Chemistry & Biochemistry, Concordia University
Matthias Ernzerhof, Département de chimie, Université de Montréal
James Gleason, Department of Chemistry, McGill University
James Hynes, Département de chimie, Ecole Normale Supérieure (France) and Department of Chemistry & Biochemistry, University of Colorado (USA)
Radu Iftimie, Département de chimie, Université de Montréal
Monique Laberge, Department of Biology, Concordia University
Guillaume Lamoureux, Department of Chemistry & Biochemistry, Concordia University
Nicolas Moitessier, Department of Chemistry, McGill University
Heidi M. Muchall, Department of Chemistry & Biochemistry, Concordia University
Xavier Ottenwaelder, Department of Chemistry & Biochemistry, Concordia University
Peter Pawelek, Department of Chemistry & Biochemistry, Concordia University
Gilles Peslherbe, Departments of Chemistry & Biochemistry and Physics, Concordia University
Christian Reber, Département de chimie, Université de Montréal
Stuart Rothstein, Departments of Chemistry and Physics, Brock University
Armand Soldera, Département de chimie, Université de Sherbrooke
Holger Vach, Département de physique, Ecole Polytechnique (France)
Panagiotis Vasilopoulos, Department of Physics, Concordia University
Dongqing Wei, Department of Biomedical Engineering, Shanghai Jiatong University (China)
Tony Whitehead, Department of Chemistry, McGill University
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