A single carbon adatom migration mechanism on (2 x 1) reconstructed diamond (001) surfaces was investigated by means of ab initio and semi-empirical quantum chemical calculations using a cluster model. The single adatom migrates preferably along the dimer rows and an anisotropic diffusion of a carbon adatom on diamond (001) surfaces was suggested to be very similar to the experimentally observed Si adatom diffusion on Si(001) surfaces. The smallest nucleus on the terrace for the crystal growth of diamond was concluded to be a dimer cluster made of two adatoms on diamond (001) surfaces.

Adatom Migrations and Nucleations on Reconstructed (001) Surfaces II. Diamond. Tsuda, M., Hata, M., Oikawa, S.: Applied Surface Science, 1996, 107, 116-21