1. See for example, Messmer RP (1979) In: Rhodin TN, Ertl G (eds) The nature of the surface chemical bond. North-Holland, Amsterdam, and Kasowski RV, Rhodin T, Tsai M-H (1986) Appl Phys A41:61 and references therein
2. Panas I, Siegbahn P, Wahlgren U (1987) Chem Phys 112:325
3. Melius CF, Upton TH, Goddard WA (1978) Solid State Comm 28:501
4. Upton TH, Goddard WA (1981) CRC Critical Reviews in Solid State and Materials Sciences
5. Bauschlicher CW, Walch SP, Bagus PS, Brundle CR (1983) Phys Rev Lett 50:864