Interpretation of the Infrared Spectra of Fused Silica

A vibrational analysis was performed for fused silica assuming short‐range order in the glassy network. This order is described by an average structural unit based on the model α‐quartz. The analysis uses a group theoretical method and the Wilson FG‐matrix techniques to predict 16 normal mode vibrational frequencies based on a diagonal force field. The most probable values of the force constants, which were obtained from the best fit between the calculated vibrational frequencies and the measured spectral values, are: image Although the selection rules are not adhered to, 15 predicted frequencies are within the ranges of the spectra of fused silica reported in the literature.