Premium
A Double Bond Charge Model for Si
Author(s) -
Klenner M.,
Falter C.,
Ludwig W.
Publication year - 1989
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.2221510210
Subject(s) - tetrahedron , covalent bond , phonon , charge density , redistribution (election) , lattice (music) , partial charge , molecular dynamics , materials science , crystal structure , charge (physics) , lattice constant , molecular physics , ion , condensed matter physics , chemical physics , chemistry , computational chemistry , physics , crystallography , quantum mechanics , diffraction , politics , political science , acoustics , law
Starting from a picture of bonding dynamics of covalent crystals based on ab‐initio density response calculations, a phenomenological model is constructed which more clearly shows the principles governing the microscopic density redistribution than does the usual bond charge model. A tetrahedral configuration is introduced of four bond charges rigidly attached to each ion, but free to rotate. The resulting system is treated by means of methods used in the lattice dynamics of molecular crystals. The accuracy of the phonon dispersion curves obtained is comparable to that of the best other models. The analogies are worked out to the microscopic partial density model and the importance of the “chains” in the crystal structure to the lattice dynamics of zinc‐blende materials demonstrated by computing the effective force constants.