The choice of basis set in quantum chemical calculations can have a huge impact on the
quality of the results, especially for correlated ab initio methods. This article provides an …

The Coupled-Cluster expansion, truncated after single and double excitations (CCSD),
provides accurate and reliable molecular electronic wave functions and energies for many …

A number of consequences of the presence of the exchange–correlation hole potential in
the Kohn–Sham potential are elucidated. One consequence is that the HOMO–LUMO orbital …

A systematic series of calculations encompassing a wide range of basis sets and correlated
methods has been used to estimate the complete basis set, full CI hydrogen bond strength in …

Highly correlated configuration interaction (CI) wavefunctions going beyond the simple
singles and doubles (CISD) model space can provide very reliable potential energy …

An assortment of 1-and 2-electron water properties were extracted from a systematic
sequence of wave functions. The regularity inherent in this sequence permitted simple …

Based on the theory of effective Hamiltonians, a variational procedure to calculate singlet—
triplet energy differences in diradical systems is described, which includes all the differential …

A method is presented for expressing the occupied self-consistent-field (SCF) orbitals of a
molecule exactly in terms of chemically deformed atomic minimal-basis-set orbitals that …

Spectroscopic constants for the ground states of the first row transition~ etal m? noxides and
iron monohydride have been determined from SCF and CI (SD) calculatiOns usmg …

For a closed shell ground state with no neardegeneracy effects, a Hartree-Fock calculation
followed by second-order many-body perturbation theory, MBPT2, provides reasonably …