Van der Waals density functional from multipole dispersion interactions.

We present a van der Waals density functional from high order multipole dispersion interactions between pairs of atoms. Calculated C(2m</=16) dispersion coefficients for dimers involving alkali, alkaline-earth, and noble gas atoms show mean absolute deviations in the range of 2%-6% from highly accurate calculations. This successful test indicates that this approach can yield efficient algorithms for calculation of van der Waals forces.