Evaluating dynamic multipole polarizabilities and van der Waals dispersion coefficients of two-electron systems with a quantum Monte Carlo calculation: A comparison with some ab initio calculations
Résumé
We present some systematic calculations of dynamic multipole polarizabilities and van der Waals dispersion coefficients for the helium atom and H2 molecule with a quantum Monte Carlo calculation. Using an original method based on a gauge-invariant formalism we also report some ab nitio results of the same quantities. In light of the results we discuss the advantages and drawbacks of both approaches in comparison to prior theoretical results. © 1993 The American Physical Society.