Thirdorder perturbation theory for van der Waals interaction coefficients
Abstract
The thirdorder expression for the dispersion interaction between two atoms is written as a sum over lists of transition matrix elements. Particular attention is given to the C_{9}/R^{9} interaction which occurs in the homonuclear case when one atom is in an S state and the other is in a P state. Numerical values of the C_{9} coefficient are given for the homonuclear alkalimetal dimers. The size of the C_{9}:C_{3} dispersion coefficient ratio increases for the heavier alkalimetal atoms. The C_{11} and C_{13} coefficients between two helium atoms and lithium atoms in their ground states are also given.
 Publication:

Physical Review A
 Pub Date:
 November 2011
 DOI:
 10.1103/PhysRevA.84.052502
 Bibcode:
 2011PhRvA..84e2502T
 Keywords:

 31.15.ac;
 31.15.ap;
 34.20.Cf;
 Highprecision calculations for fewelectron atomic systems;
 Polarizabilities and other atomic and molecular properties;
 Interatomic potentials and forces