ELECTRONIC AND STRUCTURAL-PROPERTIES OF GAASO4

We present first principles calculations for the electronic and struct ural properties of GaAsO4. The calculations were performed within the local density approximation using nb initio pseudopotentials and a pla ne-wave basis. We determined the lattice parameters, cohesive energy a nd bulk modulus by minimizing the total energy of the solid. We find g oad agreement for the structural properties, within about 1% of experi mentally observed values. Our cohesive energy is consistent with other local density calculations for isostructural materials. The predicted value of our bulk modulus, 32.0 GPa, is consistent with recent experi mental measurements and the value for similar materials such as AlPO4. This is in contrast to recent interpretations which have suggested a value half as large. The calculated electronic band structure, partial and total density of states and charge density are also presented. (C ) 1998 Elsevier Science Ltd. All rights reserved.