Chapter 4 Methods in Molecular Modelling 01403345 Piti

Chapter 4 Methods in Molecular Modelling 01403345 Piti Treesukol

Optimization Procedure Specify Initial Structure (R) Guess Wave Function SCF Adjust (R, r) Determine E(R, r) Calculate E/ Specify New Structure Minimum E(R, r)? Calculate E/ R Minimum E(R)? 2

Methods • Quantum Chemistry – Ab-initio Calculations – Semi-empirical Calculations – Density Functional Thoery – Plane wave calculations • Classical Chemistry – Molecular Dynamics – Molecular Mechanics • Other Approaches

Ab-initio Calculations • Hartree-Fock methods – Hartree-Fock (HF/ROHF/UHF) • �Post-Hartree-Fock methods – – – Møller-Plesset perturbation theory (MPn) Configuration interaction (CI) Coupled cluster (CC) Quadratic configuration interaction (QCI) Quantum chemistry composite methods (G 1, G 2, CBS) • Multi-reference methods – Multi-configurational self-consistent field (MCSCF) – Multi-reference configuration interaction (MRCI) – Complete Active Space Perturbation Theory

Density Functionals • เทอม และ สามารถประมาณไดจากฟงกชนนลแบบ ตาง ๆ – Local exchange functional (uniform electron gas) – Beck 88 exchange functional – Gradient-corrected correlation functional • Hybrid Method – B 3 LYP 8

Applications of Computational Chemistry 10