Premium
Model calculations of the LUC‐CNDO modulating function
Author(s) -
Smith P. V.,
Szymanski J. E.
Publication year - 1986
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221340123
Subject(s) - cndo/2 , hamiltonian (control theory) , formalism (music) , resummation , mathematics , physics , computational chemistry , mathematical physics , quantum mechanics , chemistry , molecule , mathematical optimization , art , musical , visual arts , quantum chromodynamics
Attempts to calculate the properties of the homopolar oovalent solids using the periodic large unit cell, complete neglect of differential overlap (LUC‐CNDO) formalism have invoked the so‐called k = O approximation. In response to controversies over the application of this approach we have shown that, for LUC's of intermediate (practical) size, it is necessary to introduce into the k = O LUC‐CNDO formalism an appropriate distance‐dependent modulating function. By analysing a variety of one‐dimensional tight‐binding models we have further suggested that this modulating function may be usefully approximated by the face‐centred cubic sine2 function. The main objective of this present paper is to investigate further the case for this sine2 functional form by using the model Hamiltonian representation of the covalent solids of Chadi and Cohen to compute the modulating function directly. The possibility of employing alternative, higher‐quality, LUC sampling schemes within the periodic LUC‐CNDO method is also critically examined using this model Hamiltonian approach.