Fig. 10

A Relative abundance of isolated ReO₄ complexes in fluid expressed as ratio of systems and temperatures as indicated on diagram. The relative abundance is equal to the integrated intensity ratio of the 960 cm⁻¹ Raman band (see text for discussion). The Raman bands are normalized to the same slit widths and acquisition times. Their ratio at the two different temperatures is not corrected for temperature-dependent Raman intensity (Long 1977). However, given the form of the temperature-dependence and the fact that it decreases to the fourth power with increasing Raman frequency (see Long 1977; Mysen et al. 1982b; for detailed discussion of these features), this assumption likely introduces a less than 10% error in individual intensities. Given that the same vibration in similar structural environments enters into this ration, this error likely cancels out. Relative abundance of isolated SiO₄ complexes in fluid expressed as ratio of systems and temperatures as indicated on diagram. The relative abundance is equal to the integrated intensity ratio of the 780 cm⁻¹ Raman band assigned to Si–O stretch vibrations (see text for discussion). The Raman bands are normalized to the same slit widths and acquisition times