【摘要】 <正> 羟硅铍铈矿系1976年在我国吉林省某地大型稀有稀土矿床中发现的新矿物。经多次X射线分析表明,它与硅硼钙石为似型矿物,晶体结构基本相同,其化学成分却与国内外同类矿物有较大差异,经计算该矿物分子式为: 简化后为（Ce,Y）₂Be₂Si₂O₈（OH）₂称为羟硅铍铈矿。更多还原

【Abstract】 On account of the fact that hydrogen atom is too light and thus its X-ray diffraction is extremely weak, the determination of structural positions of hydrogen atoms in minerals cannot be effected by means of traditional X-ray diffraction techniques. The rapid development of NMR technique has brought about a solution to the problem mentioned above. This technique is based on the finding that in all nuclei with magnetism, the protons have the strongest resonance absorption signals.In this paper NMR determinations of the structural positions of hydrogen atoms in yttroceberisite from a certain locality of China were performed. The results show that the mineral contains considerable amounts of hydroxyl. Characteristic resonance absorption spectrum of hydroxyl was obtained, and the line width was also measured. The second moment was first estimated from the experimental spectrum to determine the structural positions of hydrogen atoms. Then a structural model for this mineral was established with reference to the data on the structure of datolite. Furthermore, the second moment was theoretically estimated in terms of Ven Vleck’s formula. Comparison of the experimental second moment with the theoretical one shows that the structural positions of hydrogen atoms in yttroceberisite are similar to those in datolite. Our studies also indicate that hydrogen atoms are confined to their structural positions by Strong bonds.更多还原