Elektron Korelasyon Yöntemleri İçin Molekül İçi Küme Yaklaşımı

Abstract

The Cluster-in-Molecule approach is a fragmentation-based local correlation method. Basic principle of local correlation methods is that the contribution of the interaction between distant localized molecular orbitals (LMOs) to the correlation energy is negligible. The aim of this thesis study is to develop linear-scaling CIM-DF-MP2, CIM-DF-MP2.5, CIM-DF-MP3, CIM-DF-CCSD and CIM-DF-CCSD(T) methods by applying CIM and density-fitting (DF) approaches to the Moller-Pleset (MP), high cost coupled-cluster singles and doubles (CCSD) and CCSD with perturbative triples [CCSD(T)] methods, and programing with C++.