tructure and elasticity of hydrous ringwoodite : A first principle investigation
نویسندگان
چکیده
First principle calculations were performed to investigate structural, IR, and elastic properties of hydrous ringwoodite and their evolution with pressure up to 36 GPa. Hydrogen defects are introduced by creating Mgor Si-vacancies Mg1.875H0.25SiO4, Mg1.75H0.5SiO4 and Mg2Si0.875H0.5O4. Energy considerations imply that the Mg-vacancy coupled substitution will be the easiest to form, but, in the Earth, both vacancies will participate in the process. Calculated IR spectra, when compared with reported observations, suggest that both types of defects are abundant in synthetic samples. We find that (d ln VS/d ln VP) for lateral variations
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