MOLECULAR-DYNAMICS CALCULATIONS OF ENERGETICS AND GEOMETRIES OF STEPSON DIAMOND C(001)

The diamond C(001) surface has been observed by scanning tunneling mic roscopy (STM) to dimerize similar to Si(001). STM also observed the fo rmation of single- and double-layer steps in this surface. Using an ab initio multicenter molecular-dynamics method, our calculations for th e relaxed geometries and the corresponding energetics of these steps s how that the detailed structures of these steps are intrinsically diff erent from that of type A and type-B steps of Si(001) obtained by Chad i. These differences can be attributed to the preference of carbon ato ms near the edges of the lower terrace to form dimers with strong mixe d single and double bonds rather than to rebond to the edge atoms.