Computational Methods For Large Molecules And Localized States In Solids

Computational Methods for Large Molecules and Localized States in Solids

During the past few years, there has been dramatic progress in theoretical and computational studies of large molecules and local ized states in solids. Various semi-empirical and first-principles methods well known in quantum chemistry have been applied with considerable success to ever larger and more complex molecules, including some of biological importance, as well as to selected solid state problems involving localized electronic states. In creasingly, solid state physicists are adopting a molecular point of view in attempting to understand the nature of electronic states associated with (a) isolated structural and chemical defects in solids; (b) surfaces and interfaces; and (c) bulk disordered solids, most notably amorphous semiconductors. Moreover, many concepts and methods already widely used in solid state physics are being adapted to molecular problems. These adaptations include pseudopotentials, statistical exchange approxi mations, muffin-tin model potentials, and multiple scattering and cellular methods. In addition, many new approaches are being de vised to deal with progressively more complex molecular and local ized electronic state problems.

Computational Methods for Large Molecules and Localized States in Solids

Computational Methods In Quantum Chemistry, Volume 2: Quantum Chemistry

This book provides a comprehensive account, from first principles, of the methods of numerical quantum mechanics, beginning with formulations and fundamental postulates. The development continues with that of the Hamiltonian and angular momentum operators, and with methods of approximating the solutions of the Schroedinger equation with variational and perturbation methods.Chapter 3 is a description of the Hartree-Fock self-consistent field method, which is developed systematically for atoms. The Born-Oppenheimer approximation is introduced, and the numerical methods presented one by one thereafter in a logically consistent way that should be accessible to undergraduates. These include LCAO, Hartree-Fock-SCF method for molecules, Roothaan LCAO-MO-SCF method, and electron correlation energy.Chapter 4 is devoted to the more sophisticated computational methods in quantum chemistry, with an introduction to topics that include: the zero differential overlap approximation; Huckel MO theory of conjugated molecules; Pariser-Parr-Pople MO method; extended Huckel theory; neglect of differential overlap methods; invariance in space requirements; CNDO; INDO; NDDO; MINDO; MNDO; AM1; MNDO-PM3; SAM1; SINDO1; CNDO/S; PCILO,Xα; and ab initio methods.This is followed by an introduction to Moller-Plesset perturbation theory of many electrons, and coupled perturbed Hartree Fock theory, with a description of the coupled cluster method. Finally Chapter 5 applies these methods to problems of contemporary interest.The book is designed to be a junior/senior level text in computational quantum mechanics, suitable for undergraduates and graduates in chemistry, physics, computer science, and associated disciplines.