Obtaining the Varshni potential function using the 2-body Kaxiras–Pandey parameters

Abstract

A generalized version of the Varshni potential function was adopted by Kaxiras and Pandey for describing the 2-body energy portion of multi-body condensed matter. The former’s simplicity and resemblance to a Morse potential allows faster computation while the latter’s greater number of parameters allows better curve-fitting of spectroscopic data. This paper shows one set of parameter conversion from the Varshni function to the 2-body portion of the Kaxiras–Pandey function, and vice versa two sets of parameter conversion. The latter two sets reveal good correlation between plotted curves, and were verified by the imposition of equal energy curvatures at equilibrium and equal energy integral from equilibrium to dissociation. These parameter conversions can also be attained more easily by equating the product of indices (for short range) and the summation of index reciprocals (for long range).

Keywords

• derivative
• integral
• Kaxiras–Pandey
• parameter conversion
• potential function
• Varshni