Theoretical Study of Glass Systems Using ab Initio Molecular Electronic Structure Theory. 1. Lithium Metaphosphate Glass

摘要

A methodology for the theoretical study of glass systems using ab initio molecular electronic structure theory is discussed. Lithium metaphosphate glass of the formula Li2O·P2O5 is considered, and the choice of models and methods is discussed. The presence and significance of multiple minima on the potential energy surface is also discussed. Four lowest energy structures for the model (Li_2O·P_2O_5)_4 are given, and vibrational spectra are predicted and compared to experimental data. A structure that would indicate preference for the formation of P-O-P chains in the lithium metaphosphate glass is found to be the most stable energetically in the model. Good overall agreement with experimental infrared and Raman spectra is achieved.