Considering the cheap and larger substrate advantages offered by standard Si industrial processes, the integration of III-V compound semiconductors on Si (001) substrates is a way of dramatically reducing the manufacturing cost of many devices. Elucidation of surface passivation is one of the key parameters during wetting-property studies and heterogeneous epitaxy, as it fundamentally controls the growth and physical properties of composite materials and devices for photonics, electronics, or energy harvesting applications [1-3] . In this work, with the use of Density Functional Theory (DFT), we analyze the surface passivation behavior of H and III-Vs on Si by determining the absolute surface energies, and barrier energies (using nudged elastic band method). This approach is anticipated to be useful for numerous different associations of surface passivation [3,4] . We finally provide quantitative evidence using DFT simulations that the nature of monoatomic layer that forms on the substrate surface can have a significant impact on the general description of surface passivation as well as the wetting-properties and epitaxial growth of the III-V semiconductor heterostructure on Si. [1] I. Lucci et al., Physical Review Materials 2 (6), 060401 (R), (2018). [2] I. Lucci et al., Advanced Functional Materials, 28(30):1801585, (2018). [3] L. Pedesseau et al., arXiv preprint arXiv:2303.15566 (2023). [4] C. Cornet et al., Phys. Rev. Mater. 4, 053401 (2020).