Crystal structure of nesquehonite, MgCO 3H(D)O by neutron diffraction and effect of pH on structural formulas of nesquehonite

Yamamoto, Genichiro*; Kyono, Atsushi*; Abe, Jun*; Sano, Asami; Hattori, Takanori

Journal of Mineralogical and Petrological Sciences, 116(2), p.96 - 103, 2021/04

https://doi.org/10.2465/jmps.200117

Neutron diffraction, Raman spectroscopy, and thermal analysis were performed to investigate the composition, structure, and formation conditions of the magnesium carbonate hydrate nesquehonite. The time-of-flight neutron diffraction revealed the crystal structure of the monoclinic space group 2 with lattice parameters of =7.72100(12)=5.37518(7)=12.1430(3)=90.165(4), in which two deuterium atoms are coordinated to the O1, O2, and O6 atoms to form water molecules. The three water molecules in the structure suggests the structural formula of the nesquehonite should be MgCO 3HO rather than Mg(HCO)(OH) 2HO.