A basis set study of coupled cluster and full configuration interaction calculations of molecular electric properties for BH

Static and frequency-dependent polarizabilities and first and second hyperpolarizabilities have been calculated for BH using full configuration interaction (FCI) and the hierarchy of coupled cluster models CCS, CC2 and CCSD. A systematic basis set investigation has been performed and has been used to estimate basis set limit results. The FCI results are used to calibrate the accuracy of the coupled cluster model hierarchy. No systematic improvements are found in CC2 relative to CCS. The CCSD model appears to be robust and represents a significant improvement relative to CCS and CC2. The CCSD results are in close agreement with the FCI results for α and γ, while for β a similar accuracy requires considerations of a higher level in the coupled cluster hierarchy.