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Molecular Model Parameters for the Saddle‐Point Configuration of F, F A , F B , and F H Centres in the Alkali Halides
Author(s) -
Kung A. Y. S.,
Lagowski J.,
Vail J. M.
Publication year - 1980
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.2221000229
Subject(s) - alkali metal , impurity , halide , saddle point , crystallography , chemistry , type (biology) , saddle , inorganic chemistry , geometry , mathematics , ecology , mathematical optimization , organic chemistry , biology
A molecular model for the saddle‐point configuration of F‐type centres, which previously led to the correct prediction of type II emission for F A centres in RbF:Li and RbF:Na, based on an empirical parameter Z , is extended to other impurity F centres in the alkali halides. CsF:Li and CsF:Na are predicted to have type II F A centres, and a number of triangular F B centres in the NaCl structure are also predicted to be type II, particularly in materials with small host anions combined with Li + or Na + impurities. Materials having small Z values, presumed to favour type II behaviour, are also identified, for F H centres with large host anions and H −; or F −; impurities, and for F A and triangular F B centres in the CsCl structure containing Li + or Na + impurities, where the F B centre which has impurities on adjacent corners of a unit‐cube face is strongly favoured.