Calculations with the CNDO method on clusters of silver atoms

Abstract

An attempt has been made to explore the applicability of the complete neglect of differential overlap (CNDO) method for investigating clusters of silver atoms. A new parametrization for silver has been obtained by comparing charge distributions, as well as local and total density of states, from CNDO calculations with those from the Xα scattered wave (XαSW) method for an Ag7 cluster which represents a fragment of the silver lattice. These parameters have then been used for making CNDO calculations on four further clusters of the same type, namely Ag6, Ag10, Ag13 and Ag19, and the results are compared with previous XαSW calculations. These CNDO calculations give d-band widths in broad agreement with those from the XαSW method. The most significant difference is that the CNDO method gives less localization on central atoms with high coordination numbers than is found from the XαSW calculations. It is suggested that this apparent deficiency of the CNDO calculations may be less serious when the clusters are b...