@article{sremaniak_whitten_menon_lucovsky_2003, title={Contributions to the infrared effective charges of oxides and chalcogenides from equilibrium charge and dynamic charge redistribution during normal mode motions}, volume={212}, ISSN={["0169-4332"]}, DOI={10.1016/S0169-4332(03)00087-4}, abstractNote={Abstract Empirical force constant models for infrared (IR) and Raman scattering have emphasized differences between non-crystalline oxides and chalcogenides, attributing them to different bond angles at the two-fold coordinated O- and S(Se)-atoms in spite of the fact that both classes of materials form continuous random networks (CRNs) with equivalent 8 N rule bonding coordination. This article applies ab initio electronic structure calculations to determine (i) equilibrium bonding geometries, and (ii) infrared effective charges for normal mode motions of O- and S-atoms in SiO 2 , and GeS 2 and As 2 S 3 , respectively. Differences in equilibrium bond angles and normal mode effective charges are shown to result from quantitative differences in SiO, and GeS and GeSe bond ionicities that optimize the SiO 2 , and GeS 2 and As 2 S 3 total energies at markedly different bond angles.}, number={2003 May 15}, journal={APPLIED SURFACE SCIENCE}, author={Sremaniak, LS and Whitten, JL and Menon, M and Lucovsky, G}, year={2003}, month={May}, pages={839–843} }
 @article{whitten_zhang_menon_lucovsky_2002, title={Electronic structure of SiO2: Charge redistribution contributions to the dynamic dipoles/effective charges of the infrared active normal modes}, volume={20}, number={4}, journal={Journal of Vacuum Science & Technology. B, Microelectronics and Nanometer Structures}, author={Whitten, J. L. and Zhang, Y. and Menon, M. and Lucovsky, G.}, year={2002}, pages={1710–1719} }