Effect of pure volatile atmospheres on Si species: Shown here are the partial pressures of SiO₂ (top row, panels a and b), SiO (middle row, panels c and d), and Si (bottom row, panels e and f) above a BSE lava ocean. The plots in the left column show partial pressures as a function of total volatile pressure at a fixed temperature of 3000 K. The plots in the right column show partial pressures as a function of temperature at a fixed total volatile pressure of 1 bar. The partial pressures of vaporised species in an atmosphere without volatiles (grey dashed line), pure H atmosphere (dark blue), pure C atmosphere (black), pure N atmosphere (light blue), pure S atmosphere (yellow), and pure P atmosphere (light purple) above a BSE lava ocean are shown for comparison.