Frozen-core full-CI calculation of imaginary frequency-dependent dipole polarizabilities of ground state BeH 2 and the C6 dispersion coefficients of its homodimer

Abstract

Frozen-core full-CI calculations of frequency-dependent dipole polarizabilities (FDPs) of ground state BeH 2 at the experimental distance of R = 2.506 a 0 have been performed using an extended set of 208 contracted GTO functions [9s9p5d3f] on Be and [9s8p6d] on H involving about 58 × 10 6 symmetry-adapted Slater determinants. The Casimir–Polder integral was then evaluated analytically using eight optimized imaginary frequencies chosen according to a recently developed interpolation technique which allows for the evaluation of the three dipole dispersion constants for the BeH 2–BeH 2 homodimer, from which isotropic C 6 and anisotropy γ 6 coefficients are derived for the first time.