Variational calculations of dispersion coefficients for interactions among H, He, and Li atoms

The dispersion coefficients ${\mathit{C}}_6$, ${\mathit{C}}_8$, and ${\mathit{C}}_{10}$ for the interactions among H, He, and Li are calculated using variational wave functions in Hylleraas basis sets with multiple exponential scale factors. With these highly correlated wave functions, significant improvements are made upon previous calculations and our results provide definitive values for these coefficients. © 1996 The American Physical Society.