Å) with ECT=-2.41 eV. In particular, ECT is associated with orbital interactions at shortrange distances, denoting orbital overlapping in the PhosO-DMA III and PhosO-TMA III complexes, which agrees with their relative higher values of electron transfer. As can be seen, the inner-sphere surface adsorption mechanism of trivalent methylarsenicals is driven by electrostatic forces and contributed from charge-transfer (orbital) stabilization, standing for a combined contribution of 80%. With this in mind, we cannot assume hydrogen bonding as the primary interaction mechanism from the structural motif, revealing the relevance of our energy decomposition analyses. Otherwise, dispersion forces (EDISP) have a minor contribution (10-12%), comparable to polarization effects (7-11%). As a comparison, the As(III) physisorption onto intrinsic phosphorene is 28% due to dispersion energies, implying the different way as arsenicals are stabilized onto phosphorene oxide .