A general local model pseudopotential for simple metals. Binding energy and compressibility

A simple form of the local pseudopotential is demonstrated which derives from the consideration of the ion core as a square hill of strength AZ and width r_c. The actual interaction between the conduction electron and the ion core is thus taken as a sum of two terms: (i) the Coulomb interaction term -Ze²/r and, (ii) a constant repulsive term AZe² for r < r_c and 0 for r > r_c. A remarkable feature of the present pseudopotential is its astonishing success in revealing the correct position of the first node in the momentum space and simultaneously satisfying the energy minimization condition, in comparison to other forms. Calculations are performed for the total energy and the static compressibility for ten metals. On the whole, very satisfactory agreement is obtained between theoretical results and experimental data.