Interaction induced electric dipole moment and (hyper)polarizability in the dihydrogen–helium pair

Abstract

We have calculated the interaction dipole moment, polarizability and first hyperpolarizability of the dihydrogen–helium pair using flexible basis sets of Gaussian-type functions and high-level ab initio methods. Around the equilibrium position of the linear configuration (the helium-atom at a distance of R e / a 0 = 6.43 from the centre of the dihydrogen molecule) the interaction mean ( α ¯ int ) and anisotropy (Δ α int) of the dipole polarizability and the mean hyperpolarizability ( β ¯ int ) vary as [ α ¯ int ( R ) - α ¯ int ( R e ) ] / e 2 a 0 2 E h - 1 = 0.0069 ( R - R e ) - 0.0125 ( R - R e ) 2 + 0.0052 ( R - R e ) 3 [ Δ α int ( R ) - Δ α int ( R e ) ] / e 2 a 0 2 E h - 1 = - 0.0601 ( R - R e ) - 0.0052 ( R - R e ) 2 + 0.0042 ( R - R e ) 3 + 0.0020 ( R - R e ) 4 [ β ¯ int ( R ) - β ¯ int ( R e ) ] / e 3 a 0 3 E h - 2 = - 1.22 ( R - R e ) + 0.68 ( R - R e ) 2 - 0.15 ( R - R e ) 3 + 0.01 ( R - R e ) 4 at the CCSD/[6s4p3d1f/6s4p3d1f] level of theory.