  Quantum Monte Carlo methods have proven to predict atomic and bulk properties
of light and non-light elements with high accuracy. Here we report on the first
variational quantum Monte Carlo (VMC) calculations for solid surfaces. Taking
the boundary condition for the simulation from a finite layer geometry, the
Hamiltonian, including a nonlocal pseudopotential, is cast in a layer resolved
form and evaluated with a two-dimensional Ewald summation technique. The exact
cancellation of all Jellium contributions to the Hamiltonian is ensured. The
many-body trial wave function consists of a Slater determinant with
parameterized localized orbitals and a Jastrow factor with a common two-body
term plus a new confinement term representing further variational freedom to
take into account the existence of the surface. We present results for the
ideal (110) surface of Galliumarsenide for different system sizes. With the
optimized trial wave function, we determine some properties related to a solid
surface to illustrate that VMC techniques provide standard results under full
inclusion of many-body effects at solid surfaces.
