Vibrational Spectra and Structures of the Solid Phases of Germane

Abstract

This paper reports the i.r. and Raman spectra of the four solid phases of GeH4. Pure and mixed isotopic crystals have been examined. Marked spectral changes are observed at every transition. The interpretation of the spectra, based upon the Halford–Hornig approach, provides information on the crystal structure of each form. Phase I is plastic and molecules probably lie at sites of symmetry T or Td. The spectra of the two intermediate phases are consistent with site symmetries of either D2d, S4, C3v or C3 but the two former are favored. The stable phase below 63 °K is of lower symmetry, the molecules lying at sites of either D2, C2v, C2, C5, or C1, symmetry. Possible factor groups are proposed for phases II, III, and IV. The molecules are found to occupy only one set of equivalent sites in each of the phases.