PERIODIC DENSITY-FUNCTIONAL STUDY ON V2O5 BULK AND (001)SURFACE

Density functional calculations on periodic models are performed to in vestigate the structural and electronic properties of both V2O5 bulk a nd (001) surface. Full geometry optimizations of both V2O5 bulk and (0 01) surface are presented. For the bulk, the optimized structure is ve ry close to the experimental one, the calculated band gap and binding energy are in very good agreement with experimental values, from popul ation analysis it is observed that vanadyl oxygens are least ionic (O- 0.37), doubly coordinated oxygens are ionic (O-0.56), while triply coo rdinated oxygens become the most ionic (O-0.68). The structural and el ectronic properties of the surface are very close to those of the bulk . The interlayer interaction is mainly electrostatic and is found to b e 4 kcal/mol. Surface acidic and basic properties are described in ter ms of projected density of states analysis. (C) 1998 Elsevier Science B.V. All rights reserved.