Figure 13 shows the the oxygen atom speciation, as expressed by the fractions f_{O(II)}, f_{O(III)}, f_{PO(II)P}, f_{PO(II)Ti}, f_{TiO(II)Ti}, f_{PO(III)2Ti} and f_{TiO(III)2Ti}, found from (a) the analytical model and (b) the AIMD simulations.