The nuclear spin-spin coupling constant in He-2

The scalar nuclear spin-spin coupling constant was calculated for the heliu m dimer using full configuration interaction (FCI) and EOM-CCSD methods. Th e Fermi-contact was found to have nonnegligible value of 1.3 Hz at R=5.6 a. u., while the other contributions are zero. This suggests that the nuclear spin-spin coupling constants transmitted through van der Waals interactions are a much more common phenomenon than previously thought. All contributio ns exhibit sharp exponential decay with the internuclear distance. (C) 2000 American Institute of Physics. [S0021-9606(00)31248-X].