Ernest R. Davidson

Isotropic hyperfine properties have been obtained for the second row elements Al–Cl using a systematic composite approach consisting of a sequence of core/valence correlation consistent basis sets, up through aug-cc-pCV7Z, along with configuration interaction and coupled cluster methods. The best nonrelativistic final values for the atomic ground states (in MHz) are −1.80 27Al (2Po1/2), −24.31 29Si (3P0), 63.70 31P (4So3/2), 20.77 33S (3P2), and 35.42 35Cl (2Po3/2). We find a large K shell contribution to the spin density at the nucleus that is almost canceled by the L and M shell contributions. The spin density in atomic units is approximately linear with respect to the atomic number.