Integration of III-V semiconductors on Si (001) substrates is of great interest for photonic, electronic, and energy harvesting devices. [1-3] In this study, we show how the atomic arrangement of the III-V/Si interface affects the system's wetting characteristics. Using density functional theory, we first demonstrate how it is possible to investigate the variations of the absolute interface energy with the chemical potential in heterogeneous materials systems. Especially, we show that charge compensated III-V/Si interfaces are remarkably stable over a large range of chemical potential in agreement with the Electron counting model. [4,5] Although it is anticipated that stable compensated III-V/Si interfaces would normally favor complete wetting conditions, it is found that this can be easily balanced by the substrate's initial passivation, which favors in turn partial wetting conditions. Finally, we highlight how surface passivation is crucial in wetting property investigations during heterogeneous epitaxy. This research was supported by the French National Research NUAGES Project (Grant no. ANR-21-CE24- 0006). DFT calculations were performed at FOTON Institute, and the work was granted access to the HPC resources of TGCC/CINES under the allocation A0120911434 and A0140911434 made by GENCI. [1] I. Lucci, S. Charbonnier, L. Pedesseau, M. Vallet, L. Cerutti, J.-B. Rodriguez, E. Tournié, R. Bernard, A. Létoublon, N. Bertru, A. Le Corre, S. Rennesson, F. Semond, G. Patriarche, L. Largeau, P. Turban, A. Ponchet, and C. Cornet, Phys. Rev. Materials 2(6), 060401 (2018) [2] I. Lucci, S. Charbonnier, M. Vallet, P. Turban, Y. Léger, T. Rohel, N. Bertru, A. Létoublon, J. Rodriguez, L. Cerutti, E. Tournié, A. Ponchet, G. Patriarche, L. Pedesseau, and C. Cornet, Adv Funct Materials 28(30), 1801585 (2018). [3] C. Cornet, S. Charbonnier, I. Lucci, L. Chen, A. Létoublon, A. Alvarez, K. Tavernier, T. Rohel, R. Bernard, J.-B. Rodriguez, L. Cerutti, E. Tournié, Y. Léger, M. Bahri, G. Patriarche, L. Largeau, A. Ponchet, P. Turban, and N. Bertru, Phys. Rev. Materials 4(5), 053401 (2020) [4] O. Supplie, S. Brückner, O. Romanyuk, H. Döscher, C. Höhn, M. M. May, P. Kleinschmidt, F. Grosse, and T. Hannappel, Phys. Rev. B 90, 235301 (2014). [5] S. Pallikkara Chandrasekharan, I. Lucci, D. Gupta, C. Cornet, and L. Pedesseau, Phys. Rev. B 108(7), 075305 (2023).