12

Ab initio Method/First Principle Calculation

Based on Solution of Schrödinger Equation

Works well for H atom only. For all other atoms, approximations are needed

Robert Parr (Caltech)

1950

[288]

13

Hartree Fork Method and Slater Determinant

Uses the variational theorem (which is wavefunction based approach using mean field approximation)

Approximate solution is obtained. It is a form of Ab initio method.

[289]

14

Evolution of Hartree Fork Method

Self-Constrained Field (SCF) Method

Evolution of HF Method

Approximate solutions

[289]

Møller-Plesset (MP) perturbation (MP 1)

Hamiltonian is divided into two parts H ^ = H ^ 0 + λ V ^ and solved

ψ and energy are HF ψ and HF energy

[289]

MP 2

ψ remain same, energy is changed

ψ is treated by the help of summations

[289]

Density Functional Theory (DFT)

Energy of system is obtained from electron density

Approximation based

1996

[290] [291] [292]

15

Interatomic Potential

Explain Interaction of atoms in a system in terms of potentials

Limited by Accuracy, Transferability and Computational Speed of System

Multi (Many) Body Potentials Daw Baska (Sandia National Labs)

1984

[293]