Correlation between pseudopotential radii and interatomic distance and evaluation of bond characters for transition and lanthanide elements

Abstract

On the basis of a simple sp-bonding scheme, an empirical linear correlation is obtained between interatomic distances of elemental substances and the weighted average pseudopotential radii which are calculated from Zunger's s and p pseudopotential radii by considering the outermost electronic configuration. Using this empirical linear correlation and the weighted pseudopotential radii, interatomic distances of 178 closed- and open-shell sp-bonded compounds are calculated within 10% accuracy with the exception of only a few compounds. It is suggested that deviations of the calculated interatomic distances from the observed values arise from the differences in d electron contributions, high covalencies and some contributions of p-character in the light (ns) N elements. Again with the exception of only a few compounds, interatomic distances for 101 transition metal and 242 lanthanide compounds are also reproduced within 10% accuracy by the effective pseudopotential radii of these elements, which are determined by the empirical correlation for sp-bonded elemental substances and the pseudopotential radii of Zunger. Furthermore, the ratios of the sd hybridization effect in transition elements and lanthanide elements are proposed on the basis of this empirical correlation.