Critical points of metallic fluids

The interaction energy of virtual atoms overlapping by the classically accessible spheres of partially free valence electrons has been calculated at typical conditions of the critical points of metallic fluids. The distance of maximum approach of atoms has been found to be about the classical radius of the electronic shells. A model of ellipsoidal atomic cells circumscribing the classically accessible spheres of excited electrons has been developed. The probability distribution of the cells, rounded to different degree under the electron excitation, turns out to be almost uniform. The interaction energy has been found by solving the pseudowave equation with a quasiclassical percolation condition for partially free electrons. The averaged interaction energy is nearly one-third of the Madelung energy in the classical model of the one-component plasma. Using a van der Waals-like equation of state, the critical parameters of metallic plasmas have been expressed by the atomic characteristics. As an example, the critical point of metallic cesium plasma has been estimated to about 15% accuracy.