Exploration of Parameters of Ashcroft’s Potential Using Monovacancy Formation Energy and Different Exchange and Correlation Functions for some Trivalent FCC Metals
A pseudopotential approach has been used to study the variation of the vacancy formation energy as a function of the parameter of Ashcroft's empty core model potential (AECMP) and nine different exchange and correlation functions (ECF) for some trivalent fcc metals, viz. Al, La, Sc, γ-Ce, Pr and Yb. The criterion used is that should be greater than the Bohr radius ( ). There is a systematic increase in the fitted value of in going from one ECF to another, as follows: KK < Sham < GV < Kle < Harr < VS < Tay < Hub < MD and it is difficult to assign a particular value of for all ECFs for a particular trivalent fcc metal. The inherent simplicity of AECMP makes it difficult to have a universal parameter for all types of atomic property calculations.
David J. Fisher
A. Ghorai "Exploration of Parameters of Ashcroft’s Potential Using Monovacancy Formation Energy and Different Exchange and Correlation Functions for some Trivalent FCC Metals", Defect and Diffusion Forum, Vol. 294, pp. 113-118, 2009