Abstract
The moderately long-range interaction energies of degenerate atoms for nonresonant cases have been studied throughout the moderately long-range region. Extensive tabulation of necessary parameters and atomic properties for the calculation of the first-order quadrupole-quadrupole interaction energies has been made. Higher multipole interactions also have been considered and it has been shown that the series of the first-order Coulombic interaction energies converges very fast throughout the long-range region for atoms in the ground configuration. The effects of atomic spin-orbit splitting have been considered explicitly. It has been shown that () coupling and intermediate coupling may be important for the interactions between B, C, O, Al, Si, and Sc atoms in the relatively short internuclear separation range. For other atoms, the () coupling scheme will give satisfactory results throughout the long-range region. The experimental determination of the moderately long-range interatomic forces from predissociation data also has been discussed.
The estimated van der Waals dispersion energies for the first-row atoms are shown to be of almost the same size as the quadrupole-quadrupole interaction energies at the separation of twice the sum of the atomic radii. It has been also shown that the leading term [] of the magnetic interaction energy of two degenerate atoms is 10∼20% of the quadrupole-quadrupole interaction energy at through the third-row atoms.
DOI:https://doi.org/10.1103/RevModPhys.39.911
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