@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={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 8N 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 SiO2, and GeS2 and As2S3, 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 SiO2, and GeS2 and As2S3 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} }