  We report on a many-electron wavefunction theory study for the reaction
energetics of hydrogen dissociation on the Si(100) surface. We demonstrate that
quantum chemical wavefunction based methods using periodic boundary conditions
can predict chemically accurate results for the activation barrier and the
chemisorption energy in agreement with experimental findings. These highly
accurate results for the reaction energetics enable a deeper understanding of
the underlying physical mechanism and make it possible to benchmark widely used
density functional theory methods.
