The complete $O\left({\alpha }^2\right)$ correction to the long-range interaction between neutral closed-shell atoms is obtained, the relation to the asymptotic expansion of the known short-range interaction at the atomic scale is presented and a general interaction potential that is valid in the whole range of the interatomic distances is constructed.

• Received 31 March 2005

DOI:https://doi.org/10.1103/PhysRevA.72.062706