Static dipole polarizabilities of Li2, Na2, and K2.

Static dipole polarizability functions (α|| and α⊥) and thermally averaged isotropic polarizabilities (α) of Li2, Na2, and K2 in their electronic ground states have been obtained from all-electron SCF+valence CI calculations which include core polarization effects by use of an effective potential. As a function of internuclear separation, α⊥ shows a monotonic increase in all three cases while α|| exhibits a pronounced maximum at about 1.5 Re. For T=300 K, we find α(Li2)=214, α(Na2)=262, and α(K2)=477 a.u. Our results, to which we attribute an uncertainty of 2%, support the measured value for the average polarizability of Li2 [R. W. Molof et al., J. Chem. Phys. 61, 1816 (1974)] but disagree with their results for Na2 and K2. For these dimers, Molof ’s mean experimental values appear to be in error by 33% and 18%, respectively. [ABSTRACT FROM AUTHOR]