``On the Orbital Dependence of Compact, Weight-Selected Configuration Interaction and Coupled-Cluster Wave Functions,'' M. L. Abrams and C. D. Sherrill, Mol. Phys. 103, 3315-3320 (2005).

We recently reported that very compact coupled-cluster wave functions may be generated by selecting the most important configurations, by weight, from the full coupled-cluster wave function. Here, we consider how the choice of orbitals may affect these wave functions in the case of the symmetric dissociation of H2O. We employ unrestricted Hartree-Fock and complete-active-space self-consistent-field orbitals, as well as natural orbitals derived from a coupled-cluster singles and doubles wave function. For a given accuracy, some choices of orbitals can reduce the size of configuration interaction wave functions, but they have little effect on the weight-selected coupled-cluster wave functions.