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)




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.



Evolution of Hartree Fork Method

Self-Constrained Field (SCF) Method

Evolution of HF Method

Approximate solutions


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


MP 2

ψ remain same, energy is changed

ψ is treated by the help of summations


Density Functional Theory (DFT)

Energy of system is obtained from electron density

Approximation based


[290] [291] [292]


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)