Atomic structure of the c(2x2) Si/Cu(110) surface alloy from ab initio calculation

The structural properties of the c(2 X 2) Si/Cu(110) surface alloy are investigated by means of ab initio total energy calculations. They are performed with the generalized gradient correction to the local density approximation of the density functional theory and a pseudopotential approach. The results show an inward displacement of the silicon atoms and the usual surface interlayer oscillations. They are in good agreement with experiments. Surface charge density plots evidence the formation of Si-Cu bonds and the inward displacement of the silicon atoms is related to a chemical effect. [S0163-1829(99)01432-0].