Proofs are given that the cohesive energy of liquid alkali metals tends to zero at the critical point. This leads to the conclusion that, in a case of alkali metals, the Coulomb energy of interaction at the critical density is very close in magnitude to the ionization potential of the isolated atoms.

• Received 1 October 1992

DOI:https://doi.org/10.1103/PhysRevB.47.12260