Utilization of Transferability in Molecular Orbital Theory

Abstract

Publisher Summary This chapter discusses the utilization of transferability in molecular orbital theory. The chapter elaborates on the ways in which transferability can be utilized in the construction of wavefunctions for large systems. The chapter explores those methods that use such transferability to mimic ab initio calculations on large molecules, and the role played by transference in improving the numerical convergence of self-consistent field (SCF) cycling procedures. Within the molecular orbital theory, the transference of matrix elements from one molecule to another and their possible use in the construction of wavefunctions for large systems forms a natural alternative to the transferability of the parts of a wavefunction, such as localized orbitals. The chapter discusses various methods involving the transfer of matrix elements that includes the Non EmpiricaI Molecular Orbital (NEMO) scheme, and Simulated Ab initio Molecular Orbital (SAMO) scheme. The chapter presents the transference methods involving the use of localized orbitals, and finally considers the use of both transferred matrix elements and transferred localized orbitals in improving the efficiency of SCF cycling procedures.