Designed nonlocal pseudopotentials for enhanced transferability

A pseudopotential generation method is presented which significantly improves transferability. The method exploits flexibility contained in the separable Kleinman-Bylander form of the nonlocal pseudopotential [Phys. Rev. Lett. 48, 1425 (1982)]. By adjusting the functional form of the local potential, we are able to improve the agreement with all-electron calculations. Results are presented for the H, Si, Ca, Zr, and Pb atomic pseudopotentials. Configuration testing, logarithmic derivatives, chemical hardness, and structural tests all confirm the accuracy of these pseudopotentials. [S0163-1829(99) 14715-5].