Accurate dipole polarizability for Cl₂(X¹Σ⁺_g)

Abstract

Finite-field self-consistent field and fourth-order many-body perturbation theory with single, double and quadruple substitutions from the reference wavefunction calculations are reported for the static dipole polarizability (α_αβ) of chlorine CL₂(X¹Σ⁺ _g). The R/a₀ dependence of the mean dipole polarizability (α) and the anisotropy (Δα) around the experimental equilibrium bond length of R _e = 3.756776a₀ is very well approximated by

, .

The present estimates of α_zz, α_xx, α and Δα at the ground vibrational state are 42·29, 25·32, 30·98 and 16·97e²a² ₀E^-1 _h, respectively and should be the most accurate theoretical values currently available.