ABSTRACT
Theory and modeling methods can be conveniently classified into four groups, depending on the length scale and timescales to which they apply: electronic, atomistic, mesoscale, and continuum. The atomistic level methods such as Monte Carlo (MC) and molecular dynamics (MD) simulation are less demanding, enabling systems of thousands or millions of atoms to be studied over time intervals of 10 or 100 ns, depending on system size and complexity. Computationally more demanding, but still widely used, is a parameterized version of a total energy functional based on the linear combination of atomic orbitals (LCAO) electronic Hamiltonian. MD simulation method calculates the time-dependent behavior of a system. The potential depends on the positions of the particles but contains no explicit time dependence. MC and MD simulations are limited by the accuracy of the force field used and by the speed of the computers.
