MT26015 – SJTU – Fall/Winter 2019-2020

Modeling Materials

— electronic, atomistic and multiscale techniques

Lecturers

Prof. Zhaohui Jin (atoms)

Prof. Lingti Kong (electrons)

School of Materials Science and Engineering

Shanghai Jiao Tong University

September 18, 2019

Contents

Part I Introduction

1.1 Multiscale materials

1.2 Materials modeling and simulations

1.3 Continuum modeling

Contents (in many ways, open)

Part II Atomistic (Prof. JIN)

2.1 Empirical atomistic models of materials

2.2 Molecular statics

2.3 Molecular dynamics

2.4 Hand-on sessions

(a) Lattice constant and bulk modulus of perfect crystals

(b) Point defects: vacancy and interstitial

(c) Planar defects: surfaces, interfaces/grain boundaries and stacking faults

(d) Line defects: screw and edge dislocations in bcc or fcc lattices

Contents

Part III Electronic (Prof. KONG)

3.1 Principles of quantum mechanics

3.2 Density functional theory

3.3 Band structure calculations

3.4 Hand-on sessions

(a) Single point energy calculation

(b) Perfect crystals: lattice constant and bulk modulus (metals and

semiconductors)

(c) Energy level of a hydrogen atom

(d) Bond length and bond energy of H2 molecule

(e) Band structure calculation: Si, Fe and graphene

“Hand-on session”

Atomistic part will be done HERE

Electronic part in CMS computer room

MSE Building F310 (材料F楼310)

where server and PCs are based on Linux environments

http://cms.sjtu.edu.cn/gs (Chinese & English)

Wednesday

SJTU course calendar

Week #

Sept Oct Nov Dec Jan

Atomistic Electronic

X

Part I Introduction

The Computational Materials Science

“A new way of thinking …”

Why?

1st Ed. 1949

8th Ed. 2004

new chapters includes

41 chapters, 2080 pages

28 pages， 536 references

11 pages， 18 references

S. Yip (ed.), Handbook of Materials

Modeling, (Springer 2005).

However, our data is still very limited…

Published in 2011

All materials show “multiscale” characters

Understanding materials depends on fundamental theory,

practical methods, new techniques

Orowan’s “experiment”

Egon Orowan, 1901—1989

Together with G.I. Taylor and Michael Polanyi, he

was responsible for the introduction of the crystal dislocation

into physics as the essential mediator of plastic deformation.

The watch Cu-Ni 合金 牛骨

Conclusion

(1) Observation based on single experiment underlies many possibilities

(2) Understanding of material behavior depends on observations into details

HRTEM

“easy” to observe, yet difficult to measure

Not only to observe, but to measure

modeling

Bubble Raft modelingW.L. Bragg (1947)：does dislocation exist？(see the Feynman Lectures on Physics (Vol. II) 30-9/10)

grain

boundaries

Modeling simply by thinking

and playing!

Dr. Herbert Gleiter

(~1980) what happens if full of grain boundaries?

（grain size < 100 nm）The farther of nanostructured materials

‘modeling’ and ‘simulation’

model

Simulation

Good news

We have computers so we don’t even use bubbles now!

It describes the classical scientific method of formulating a simplified imitation of a real situation with preservation of its essential features.

In other words, a model describes a part of a real system by using a similar but simpler structure.

Simulation is essentially the putting of numbers into the model and deriving the numerical end-results of letting the model run or playing with the model.

Therefore, a simulation can never be better than the model on which it relies.

R.W. Cahn, The Coming of Materials Science (Amsterdam: Pergamon, 2001).

Chinese version:“走进材料科学” 化学工业出版社（2008）

What are great

challenges in modern

materials science and

engineering?

Characteristic ‘time & length’ scales

Raabe, D. ( 1998) Computational Materials Science (Wiley-VCH, Weinheim).

Kinetics of materials

From Raabe, D. ( 1998)

David L. McDowell, Materials Science and Engineering R 62 (2008) 67–123

Multiscale modeling == building-up links based on multiscale considerations

Reference book

“Introduction to materials modeling”， Ed. Zoe Barber，The Institute of Materials, Minerals and Mining 2005

(really for beginners)

The Secret Life Of Vortices

Atomistic modelling —

molecular dynamics (MD) methods

MD simulation

Observing and measuring atoms in a virtual lab

The Secret Life Of

Your Atoms

Key

data

Materials

MS-P relation

HPC – HTC

Criteria — Models

(mining-meshing)

Data analyses

Data base

Multiscale modeling

Mechanisms

Expt.—Theory

（laws）

Material Gnome / Informatics Concept