الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
In this study, -the complete energy–band structure ;f flourite¬type crystals has been obtained theoritically, The crystal of
CaF2 was chosen as a representative of the flourite crystals because it possesses most of the chemical and physical proper
ties of these crystals and also for its important role as a
host crystal in maser and laser, The calculations were based
on a local pseudopotential method comb-IlUied with the symmetrized plane–wave method. This is the first time to use such a method
for CaF2. The pseudopotential formfactors of,CaF2 have been
determined by best fitting the theoritioul results to the known
experimental data. The energy gap at ’the high symmetry point F
is found to be 11.2 eV which is in quite good agreement with the previously reported data. The variation of the energy gap
with the lattice constant of CaF2 has been invet;tigated. As an application to the energy–band structure, the coefficients of
hydrostatic pressure have been calculated at point r. One hop
es, in the futv4rc, to get, theoritically or experimentally, the
exact pseudopotential form factors. If this can be done, one can obtain a more accurate energy–band structure foT, CaF2.