The results of first-principles molecular dynamics simulations of hydrous silicate melt is reported, showing that pressure has a profound influence on speciation of the water component. It is inferred that the speciation changes from being dominated by hydroxyls and water molecules at low pressure to extended structures at high pressure. This change in structure is linked to the finding that the water–silicate system becomes increasingly ideal at high pressure, indicating complete miscibility of water and silicate melt throughout almost the entire mantle pressure regime.
- Mainak Mookherjee
- Lars Stixrude
- Bijaya Karki
