The crystal structure of julgoldite
The crystal structure of julgoldite
复制标题
朱金矿的晶体结构
DOI：
10.1017/minmag.1973.039.303.03
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发表时间：
1973
影响因子：
2.7
通讯作者：
G. Donnay
中科院分区：
文献类型：
--
作者：
R. Allmann;G. Donnay
基于2417个不对称反射，确定并精炼了julgoldite的结构，R值为4.6%，其中765个未观测到（加权R = 4.3%）。细胞尺寸为a 8·922(4),b 6·081(3),c 19·432(9)Å， β 97·60(6)°，空间群为A2/m， Z = 4, Dcalc 3·56 g cm-3。沸石矿体与水泵矿体呈等构造；在实验精度范围内，沸石中的Si-O和Ca-O距离与泵石中的相应距离相同；沸石中Fe-O的距离比泵矿中相应的(Al, Mg)-O的距离长约0·09 Å。四个羟基和o -对- oh取代的程度是通过价和计算确定的。
Summary The structure of julgoldite, , has been determined and refined to an R value of 4·6 % based on 2417 symmetry-independent reflections, of which 765 are unobserved (weighted R = 4·3 %). The cell dimensions are a 8·922(4), b 6·081(3), c 19·432(9) Å, β 97·60(6)°, the space group is A2/m with Z = 4 and Dcalc 3·56 g cm-3. Julgoldite is isostructural with pumpellyite; the Si-O and Ca-O distances of julgoldite are identical, within experimental accuracy, with corresponding distances in pumpellyite; the Fe-O distances of julgoldite are about 0·09 Å longer than the corresponding (Al, Mg)-O distances in pumpellyite. The four hydroxyl groups and the extent of O-for-OH substitution are identified by valence-sum calculations.