Fig. 4: First-principles calculation results of evaporation energy (ΔE) versus distance from the slab.

Energy difference as a function of distance to the surface for several divalent cations evaporating from the two, M1 (A) and M2 (B), sites of a slab of olivine placed in a vacuum, as obtained from first-principles calculations (details in Supplementary Materials). The plateau at high distances represents the complete evaporation state. The first 2 Å of displacement in each simulation is omitted because the energy differences in that region primarily reflect surface rearrangement structures rather than actual dissociation energies. The calculations show that Cd and Zn have lower ΔE values than Mg and Fe, indicating that Cd and Zn are more readily lost from the solid during evaporation. At the M2 site, ΔE for both Cd and Zn is extremely low, suggesting these elements can rapidly evaporate from the solid under high-temperature conditions.