Crystal structure refinements of borate dimorphs inderite andkurnakovite using B-11 and Mg-25 nuclear magnetic resonance and DFTcalculations

ISL OpenIR > 青海盐湖研究所知识仓储

	Crystal structure refinements of borate dimorphs inderite andkurnakovite using B-11 and Mg-25 nuclear magnetic resonance and DFTcalculations
	Zhou, Bing; Michaelis, Vladimir K.; Pan, Yuanming; Yao, Yefeng; Tait, Kimberly T.; Hyde, Brendt C.; Wren, John E. C.; Sherriff, Barbara L.Kroeker, Scott
	2012
发表期刊	AMERICAN MINERALOGIST
ISSN	0003-004X
卷号	97 期号:11-12 页码:1858-1865
关键词	Borate Dimorphs SalIne Lakes In Tibet B-11 Nmr Mg-25 Nmr Solid-state
摘要	Borate minerals composed of [B phi(3)] triangles and/or [B phi(4)] tetrahedra (phi = O or OH) commonly exhibit complex polymerizations to form diverse polyanion groups. High-resolution solid-state magic angle spinning (MAS) B-11 and Mg-25 NMR spectroscopy at moderate to ultrahigh magnetic fields (9.4, 14.1, and 21.1 T) allows for very accurate NMR parameters to be obtained for the borate dimorphs, inderite, and kurnakovite, [MgB3O3(OH)(5)center dot 5H(2)O]. Improved agreement between experimental results and ab initio density functional theory (DFT) calculations using Full Potential Linear Augmented Plane Wave (FP LAPW) with WIEN2k validates the geometry optimization procedures for these minerals and permits refinements of the hydrogen positions relative to previous X-ray diffraction crystal structures. In particular, the optimized structures lead to significant improvements in the positions of the H atoms, suggesting that H atoms have significant effects on the B-11 and Mg-25 NMR parameters in inderite and kurnakovite. This study shows that combined high-resolution NMR spectroscopy and ab initio theoretical modeling provides an alternative method for the refinement of crystal structures, especially H positions. Borate minerals composed of [B phi(3)] triangles and/or [B phi(4)] tetrahedra (phi = O or OH) commonly exhibit complex polymerizations to form diverse polyanion groups. High-resolution solid-state magic angle spinning (MAS) B-11 and Mg-25 NMR spectroscopy at moderate to ultrahigh magnetic fields (9.4, 14.1, and 21.1 T) allows for very accurate NMR parameters to be obtained for the borate dimorphs, inderite, and kurnakovite, [MgB3O3(OH)(5)center dot 5H(2)O]. Improved agreement between experimental results and ab initio density functional theory (DFT) calculations using Full Potential Linear Augmented Plane Wave (FP LAPW) with WIEN2k validates the geometry optimization procedures for these minerals and permits refinements of the hydrogen positions relative to previous X-ray diffraction crystal structures. In particular, the optimized structures lead to significant improvements in the positions of the H atoms, suggesting that H atoms have significant effects on the B-11 and Mg-25 NMR parameters in inderite and kurnakovite. This study shows that combined high-resolution NMR spectroscopy and ab initio theoretical modeling provides an alternative method for the refinement of crystal structures, especially H positions.
文献类型	期刊论文
条目标识符	http://ir.isl.ac.cn/handle/363002/2017
专题	青海盐湖研究所知识仓储
推荐引用方式 GB/T 7714	Zhou, Bing,Michaelis, Vladimir K.,Pan, Yuanming,et al. Crystal structure refinements of borate dimorphs inderite andkurnakovite using B-11 and Mg-25 nuclear magnetic resonance and DFTcalculations[J]. AMERICAN MINERALOGIST,2012,97(11-12):1858-1865.
APA	Zhou, Bing.,Michaelis, Vladimir K..,Pan, Yuanming.,Yao, Yefeng.,Tait, Kimberly T..,...&Sherriff, Barbara L.Kroeker, Scott.(2012).Crystal structure refinements of borate dimorphs inderite andkurnakovite using B-11 and Mg-25 nuclear magnetic resonance and DFTcalculations.AMERICAN MINERALOGIST,97(11-12),1858-1865.
MLA	Zhou, Bing,et al."Crystal structure refinements of borate dimorphs inderite andkurnakovite using B-11 and Mg-25 nuclear magnetic resonance and DFTcalculations".AMERICAN MINERALOGIST 97.11-12(2012):1858-1865.