BONDING OF HYDROGEN IN CRYSTALLINE BORON-NITRIDE

We investigate the nature of hydrogen bonding in cubic (c-BN) and hexa gonal boron nitride (h-BN) using a density-functional based nonorthogo nal tight-binding scheme. By conjugate gradient methods, we determine stable and metastable bonding positions in fully geometrically optimiz ed crystalline bulk supercells. We describe the geometries and electro nic bonding properties in detail and classify the energetic order of t he various defects. (C) 1997 Elsevier Science Ltd.