AB-INITIO APPROACH TO COHESIVE PROPERTIES OF GDN

We apply ab initio quantum-chemical methods to calculate correlation e ffects on cohesive properties of GdN, thereby extending the recently p roposed incremental method to rare-earth compounds. Our calculated val ues are in reasonable agreement with the experimental cohesive energy (86.0%) and the experimental lattice constant (102.0%). Furthermore, w e calculate a bulk modulus of 140.3 GPa. Taking into account estimates for the effect of a better basis both at the one-particle level and a t the many-particle level, we even reach 98.5% of the experimental coh esive energy and 101.3% of the experimental lattice constant. For this estimate, we obtain a bulk modulus of 163.8 GPa.