Accuracy, Timing and General Applicability of the MRD-CI Method

Abstract

The configuration interaction method is generally acknowledged to be a quite useful means of obtaining correlated wavefunctions and energies for the electronic states of atoms and molecules. The theory behind this approach is very straightforward but in applying it to practical problems of chemical interest certain computational problems arise, particularly if it is desired to extend the calculations to the limit of a full CI in a large AO basis. In essence all the CI method involves is the formation of a matrix representation of the non-relativistic electronic Hamiltonian (within the framework of the Born-Oppenheimer Approximation [1]), followed by solution of the associated secular equation (diagonalization).