Quantum Chemistry

This module provides an introduction to the most popular computational methods for studying the electronic structure and properties of molecules. Theory is combined with ‘hands on’ practical experience with the applications of quantum chemistry to obtain information about molecular orbitals, molecular geometries, transition states.

Such computational work has become an essential part of academic and industrial research. A look at a recent issue of the Journal of the American Chemical Society will reveal that experimentalists often use quantum-chemical calculations to explain results obtained in the lab, as well as to make predictions to be verified by further experiments.

You will learn how to perform state-of-the-art quantum-chemical calculations and become able to use these in a number of situations, including applications in synthetic chemistry (calculation of reaction paths), accurate prediction of physical properties (for example, dipole moments and Gibbs free energies), and interpretation of spectra (XPS, IR, UV).

Topics

General Overview of Electronic Structure Theory, The Hartree-Fock Approach, Practical Aspects of Hartree-Fock Calculations, Electron Correlation and Post-Hartree-Fock Methods and Density-Functional Theory (DFT) (12 lectures and 2 workshops)

Brief revision of quantum theory and its mathematical background. Schrödinger equation for a many-electron system. Born-Oppenheimer approximation. Electron spin. The simplest many-electron wavefunction: a Slater determinant.

Hartree-Fock equations. Occupied and virtual orbitals. Brillouin theorem. Koopmans theorem. Molecular orbitals, Hartree-Fock-Roothaan equations and the self-consistent field procedure. Interpretation of the results of Hartree-Fock calculations.

Types and properties of atomic orbital basis sets used to construct molecular orbitals. Specifying molecular geometries through Z-matrices.

Configuration interaction. Multi-configuration self-consistent field theory (MC SCF), complete-active space SCF (CAS SCF), many-body perturbation theory (MBPT).

The Hohenberg-Kohn theorem. Exchange functionals and correlation functionals. Specifics of DFT calculations.

Applications of Ab Initio and DFT Calculations (4 lectures and 2 workshops)

Introduction to an ab initio program package (GAUSSIAN or Spartan). Practical aspects of single-point calculations and geometry optimizations. Determination of transition structures and reaction coordinates. Calculation of thermochemical data and dipole moments. Examples of current applications of DFT.

Prerequisites

Chemistry Core Modules 1-9

Assessment

A written paper (70%) plus assessed workshops (30%)