Using the first-principles pseudopotential LDA approach, we have performed
calculations of the atomic and electronic structure of the (110) surface of
the cubic phase of GaN and BN. It is found that these surfaces are charact
erised by a much smaller rotation angle omega of the top atomic layer than
many other III-V(IIO) surfaces. We have found a linear correlation between
the relative vertical displacement of the cation and the anion on the surfa
ce layer (Delta,(perpendicular to)) and the surface bond length of the III-
V, II-VI and SIC compounds. In addition, we have studied the band structure
addressing the influence of the degree of ionicity on the character of the
surface states. (C) 1999 Elsevier Science B.V. All rights reserved.