Non – Nominal Value of the Dynamical Effective Charge in Alkaline – Earth Oxides
نویسنده
چکیده
We calculate ab–initio the electronic states and the Born dynamical charge Z of the alkaline–earth oxides in the local–density approximation. We investigate the trend of increasing Z values through the series, using band–by–band decompositions and computational experiments performed on fake materials with artificially–modified covalence. The deviations of Z from the nominal value 2 are due to the increasing interaction between O 2p orbitals and unoccupied cation d states. We also explain the variations, along the series, of
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