Comparative Study of Local Pseudopotentials and a New Proposal

In the pseudopotential theory, various local model potentials bearing single parameter are used frequently to study different physical and chemical properties of solids, liquids and amorphous materials. A new proposal of a local pseudopotential is put forwarded here depending on the concept of extended core radius in which half of the nearest neighbour distance is treated as effective core radius.This pseudopotential is found to satisfy all the necessary requirements for applications. With this model potential we have evaluated the form factors for several bcc, fcc and hcp metals and achieved excellent agreement with previous results. We have examined other 14 local pseudo potentials also and on the basis of the comparison, the present pseudopotential is found to be much better. As a test case study, we have evaluated phonon dispersion curves of some liquid metals, viz. Na (Z = 1), Mg (Z = 2), Al (Z= 3) and Pb (Z = 4) and obtained quite satisfactory results. From the present computations, we also conclude that it should be interesting to apply other local pseudopotentials for such comprehensive study to judge and confirm the wider applicability of the potential.