Static electric polarizability andhyperpolarizability of BCl(X 1Σ+)

Abstract

We have obtained accurate electric properties for the ground state ofboron chloride. Our work relies on finite-field self-consistent field (SCF),Møller-Plesset perturbation theory (MP) and coupled-cluster (CC)calculations with very large, systematically optimized basis sets ofGaussian-type functions. Our best values were obtained at the CCSD(T)level of theory with a [9s5p4d2f/9s7p5d2f] basis set. For the dipoleproperties we report: dipole moment µ = 0.5689 ea0, mean andanisotropy of the dipole polarizability ᾱ = 32.61 andΔα = 12.13 e2a02Eh-1, mean first β̄ = 107.0 e3a03Eh-2 and second γ̄ = 105 29 e4a04Eh-3 hyperpolarizability. For the quadrupoleproperties we report the following: quadrupole moment Θ = -2.90 ea02 andmean quadrupole polarizability C̄ = 267.47 e2a04Eh-1. The mean first and second hyperpolarizabilitydecreases monotonically around the equilibrium internuclear separation ofRe = 3.2414 a0,(dβ̄/dR)e<0 and (dγ̄/dR)e<0.Various aspects of the relative performance of the Møller-Plessetperturbation theory and coupled-cluster methods on this molecule arebrought forth and discussed.