Correlation and Localization

ISBN-13: 9783540657545 / Angielski / Twarda / 1999 / 236 str.

Peter R. Surjan; P. R. Surjan

Opis

This volume contains review and research articles in one particular ar ea of quantum chemical methodology: the theory of electron correlation and the localization problem. Correlation energy (i.e., the energy be yond the Hartree-Fock) plays an important role in the theoretical desc ription of several chemical processes (reactions, excitations, ionizat ion) while localization in quantum chemistry usually emerges as a math ematical transformation of the wave function. The connection between t hese two issues is provided by the need to evaluate correlation energy for larger molecules, which is much easier in terms of localized cont ributions. The articles selected discuss copuled cluster, perturbation al and geminal-based schemes, and cover wave function as well as densi ty based approaches.

Spis treści

Electron Correlation in Small Molecules: Grafting CI onto CC.- Extremal Electron Pairs — Application to Electron Correlation, Especially the R12 Method.- Many-Body Perturbation Theory with Localized Orbitals — Kapuy’s Approach.- An Introduction to the Theory of Geminals.- Extended Geminal Models.- Ab Initio Modern Valence Bond Theory.- Modern Correlation Theories for Extended, Periodic Systems.- Local Space Approximation Methods for Correlated Electronic Structure Calculations in Large Delocalized Systems that are Locally Perturbed.- Local Electron Densities and Functional Groups in Quantum Chemistry.- Electron Correlation and Reduced Density Matrices.- Localization via Density Functionals.