1 research outputs found
Investigation of structure and hydrogen bonding of super-hydrous phase B (HT) under pressure using first principles density functional calculations
High pressure behaviour of superhydrous phase B(HT) of Mg10Si3O14(OH)4 (Shy
B) is investigated with the help of density functional theory based first
principles calculations. In addition to the lattice parameters and equation of
state, we use these calculations to determine the positional parameters of
atoms as a function of pressure. Our results show that the compression induced
structural changes involve cooperative distortions in the full geometry of the
hydrogen bonds. The bond bending mechanism proposed by Hofmeister et al [1999]
for hydrogen bonds to relieve the heightened repulsion due to short H--H
contacts is not found to be effective in Shy B. The calculated O-H bond
contraction is consistent with the observed blue shift in the stretching
frequency of the hydrogen bond. These results establish that one can use first
principles calculations to obtain reliable insights into the pressure induced
bonding changes of complex minerals.Comment: 16 pages, 4 figure