Long-range interactions for He($nS$)--He$(n^{\prime }S)$ and He($nS$)--He$(n^{\prime }P)$

J. -Y. Zhang, Z. -C. Yan, D. Vrinceanu +2

The energetically lowest five states of a helium atom are: He($1^{1}S$), He($2^{3}S$), He($2^{1}S$), He($2^{3}P$), and He($2^{1}P$). Long-range interaction coefficients $C_3$, $C_6$, $C_8$,…