Molecular-dynamics calculations of energetics and geometries of steps on diamond C(001)

Abstract

The diamond C(001) surface has been observed by scanning tunneling microscopy (STM) to dimerize similar to Si(001). STM also observed the formation of single- and double-layer steps in this surface. Using an ab initio multicenter molecular-dynamics method, our calculations for the relaxed geometries and the corresponding energetics of these steps show that the detailed structures of these steps are intrinsically different from that of type-A and type-B steps of Si(001) obtained by Chadi. These differences can be attributed to the preference of carbon atoms near the edges of the lower terrace to form dimers with strong mixed single and double bonds rather than to rebond to the edge atoms.