1. Bilbao Crystallographic Server. The crystallographic site at the Condensed Matter; Physics Dept. of the University of the Basque Country.
http://www.cryst.ehu.es/
2. J. Muscat, V. Swamy, N.M. Harrison, Phys. Rev. B 65, 224112 (2002)
3. J. Padilla, D. Vanderbilt, Surf. Sci. 418, 64 (1998)
4. E. Heifets, R.I. Eglitis, E.A. Kotomin, J. Maier, G. Borstel, Phys. Rev. B 64, 235417 (2001)
5. M.M. Hurley, L.F. Pacios, P.A. Christiansen, R.B. Ross, W.C. Ermler, J. Chem. Phys. 84, 6840 (1986)