ISTPC/2024/postHF.md

Post Hartree-Fock Methods

1. Introduction

• Correlation energy
• Notations
• Outlines

2. Configuration Interaction (CI)

• CI wave function ansatz
• Excited determinants
• Truncated CI and Pople diagram
• Size of FCI space
• CI energy and eigenvalue problem
• Structure of the CI matrix
• Slater-Condon rules
• Size consistency

3. Perturbation Theory (PT)

• Formal Rayleigh-Schrodinger PT
• Expression of 2nd-order energy and 1st-order wave function
• Moller-Plesset PT up to 2nd order
• Pople diagram and convergence
• Computation of MP2 correlation energy (with AO-to-MO transformation)

4. Coupled Cluster (CC)

• CC wave function ansatz
• Wave operator, excitation operators, etc
• CC vs CI: cluster analysis
• Formal CC theory
• CC energy
• Pople diagram
• Variational CC
• Unitary CC
• Similarity-transformed Hamiltonian
• BCH expansion and amplitude/energy equations
• Computation of CCD energy and amplitudes