Variational calculations of dispersion coefficients for interactions   between H, He, and Li atoms
  The dispersion coefficients $C_6$, $C_8$, and $C_{10}$ for the interactions between 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. 
Zong-Chao Yan, James F. Babb, A. Dalgarno, G. W. F. Drake