The third-order 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 C9/R9 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 C9 coefficient are given for the homonuclear alkali-metal dimers. The size of the C9:C3 dispersion coefficient ratio increases for the heavier alkali-metal atoms. The C11 and C13 coefficients between two helium atoms and lithium atoms in their ground states are also given.
Physical Review A
- Pub Date:
- November 2011
- High-precision calculations for few-electron atomic systems;
- Polarizabilities and other atomic and molecular properties;
- Interatomic potentials and forces