Fig. 3
From: 29Si NMR of aqueous silicate complexes at gigapascal pressures
29Si NMR of the silicon-xylitol complex. a A high-resolution 29Si spectrum of the xylitol-Si(IV) solution, where the four-coordinate, five-coordinate, and six-coordinate silicon species are seen in solution. b 29Si NMR spectra of the same solution using the high-pressure NMR probe, measured up to 1.2 GPa (the solution froze immediately above this pressure). Note that the peak assignable to silicic acid appears with increased pressure and then disappears upon return to ambient conditions
