Chemistry Reference
In-Depth Information
9.2
MATERIAL MODELING METHODS
There are different of modeling methods currently used by the researches.
They plan not only to simulate material behavior at a particular scale of in-
terest but also to assist in developing new materials with highly desirable
properties. These scales can range from the basic atomistic to the much
coarser continuum level. The hierarchy of the modeling methods consist
quantum mechanics, molecular dynamic, micromechanics and finally con-
tinuum mechanics, that could be categorized in tow main group: atomistic
modeling and computational mechanics.
9.2.1 COMPUTATIONAL CHEMISTRY (ATOMISTIC
MODELING)
The atomistic methods usually employ atoms, molecules or their group
and can be classified into three main categories, namely the quantum me-
chanics (QM), molecular dynamics (MD) and Monte Carlo (MC). Other
atomistic modeling techniques such as tight bonding molecular dynamics
(TBMD), local density (LD), dissipative particle dynamics (DPD), lattice
Boltzmann (LB), Brownian dynamics (BD), time-dependent Ginzburg-
Lanau method, Morse potential function model, and modified Morse po-
tential function model were also applied afterwards.
9.2.1.1
QUANTUM MECHANICS
The observable properties of solid materials are governed by quantum me-
chanics, as expressed by solutions of a Schrödinger equation for the mo-
tion of the electrons and the nuclei. However, because of the inherent dif-
ficulty of obtaining even coarsely approximate solutions of the full many
body Schrödinger equation, one typically focuses on reduced descriptions
that are believed to capture the essential energetic of the problem of Inter-
est Tow main quantum mechanics method are “Ab initio” and “density
function method (DFT).”
Unlike most materials simulation methods that are based on classical
potentials, the main advantages of Ab initio methods, which is based on
first principles density functional theory (without any adjustable param-
eters), are the generality, reliability, and accuracy of these methods. They
