  Here, we quantitatively determine the impact of III-V/Si interface atomic
configuration on the wetting properties of the system. Based on a description
at the atomic scale using density functional theory, we first show that it is
possible to determine the absolute interface energies in heterogeneous
materials systems. A large variety of absolute GaP surface energies and GaP/Si
interface energies are then computed, confirming the large stability of charge
compensated III-V/Si interfaces with an energy as low as 23 meV/\r{A}$^{2}$.
While stable compensated III-V/Si interfaces are expected to promote complete
wetting conditions, it is found that this can be easily counterbalanced by the
substrate initial passivation, which favors partial wetting conditions.
