Consistency condition in the energy expression of the pseudopotential theory of metals and unified study of alkali metals

✍ Scribed by D. Sen; S. K. Sarkar; S. Sengupta; D. Roy

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 669 KB
• Volume: 115
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2221150231

✦ Synopsis

Abstract

From a careful analysis of the energy expression of the second‐order pseudopotential theory, the reason for the breakdown of the consistency condition is pointed out. The problem is resolved by introducing the concept of local volume strain which introduces some modifications in the dynamical matrix and leads to the equality of static and dynamic elastic constants. A unified study of the alkali metals with the Heine‐Abarenkov model pseudopotential in conjunction with Taylor's dielectric function, and taking proper care of the consistency condition, yields satisfactory results for both the static and dynamic properties of these metals. One interesting feature of the present investigation is that the theory satisfying the consistency condition reproduces the crossing of the longitudinal and transverse branches in the (100) direction for Li, while reproducing the normal behaviour for the dispersion curve of other metals.