A reverse Monte Carlo study of the structure of vitreous V2O5

Our earlier X-ray diffraction (XRD) data of amorphous vanadium pentoxide, V 2O5, prepared by rapid quenching (twin-roller technique) were re-examined b y reverse Monte Carlo simulations. The model networks are in agreement with the conclusions made earlier in the literature that vitreous V2O5 is const ructed from a mixture of VO5 and VO4 units. A significant fraction (18%) of terminal oxygen atoms exists while threefold-coordinated oxygen sites and VO6 units play a minor role. The VO5 groups are similar with trigonal bipyr amids rather than with the square pyramids, which are known from the crysta l structure of V2O5. (C) 1999 Elsevier Science Ltd. All rights reserved.