The computational investigation of the phase transition from the GeO2 alpha-quartz structure to the rutile structure

We report a detailed computational investigation using several techniques relating to the phase transition from the alpha-quartz to the rutile structure for GeO2 and GeO2/SiO2 solid solutions. We calculate an activation barrier of approximately 47 kJ mol(-1) for the phase transition, which is in good agreement with the most recently reported experimental value. We also identify a number of interesting intermediate structures, in which Ge is present in two coordination environments (fourfold and sixfold). These complex intermediates have characteristics akin to the experimentally observed amorphous systems. (C) 1996 Academic Press.