Open AccessEMPIRICAL PARAMETERIZATION OF INTER-IONIC POTENTIALS FOR ALKALINE EARTH FLUORIDES
Author(s) -
Songlin Feng,
Qinhan Jin,
Zhenya Guo,
Baohui Li,
Datong Ding
Publication year - 1998
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.47.1811
Subject(s) - ionic bonding , materials science , ionic potential , ion , alkaline earth metal , dielectric , crystal (programming language) , lattice energy , crystal structure , thermodynamics , chemical physics , physics , chemistry , metal , crystallography , optoelectronics , computer science , metallurgy , programming language , quantum mechanics
When the functional forms of non-coulombic inter-ionic short-range potentials have been defined, the bulk properties of ionic crystals can be calculated. The parameters presented in potential functions are determined by fitting procedure, to reproduce as colsely as possible the measured crystal data. In the present study, the shell model is employed for the investigations of CaF2, SrF2 and BaF2 ionic crystals. Remarkable feature of the present fitting procedure is that shell charges are sure to be negative and recent experimental data are adopted. The anion (F-) charge, which is assumed to be common to the three fluorides, is adjusted to 0.97e. In so doing, the obtained model parameter set is able to produce a satisfactory agreement between the calculated results and the experimental data, such as lattice formation energies, elastic constants, dielectric constants, ionic polarizabilities, transverse optic and Raman frequencies, for the alkaline earth fluorides.