Piemontite
Nagashima M, Akasaka M
American Mineralogist 89 (2004) 1119-1129
An X-ray Rietveld study of piemontite on the join
Ca2Al3Si3O12(OH) - Ca2Mn3+3Si3O12(OH) formed by hydrothermal synthesis
Sample: q = 0.5, p = 0.5, Synthesis at P=350 MPa, T=500 C
_database_code_amcsd 0003586
8.856 5.6291 10.148 90 115.516 90 P2_1/m
atom     x    y    z occ
Ca1   .757  3/4 .155
Ca2   .603  3/4 .421
AlM1     0    0    0 .99
MnM1     0    0    0 .01
AlM2     0    0  1/2 .96
AlM2     0    0  1/2 .04
AlM3  .298  .25 .222 .55
MnM3  .298  .25 .222 .45
Si1   .332  3/4 .046
Si2   .682  .25 .275
Si3   .186  3/4 .317
O1    .232 .991 .036
O2    .301 .986 .358
O3    .789 .013 .352
O4    .065  .25 .135
O5    .042  3/4 .147
O6    .063  3/4 .399
O7    .521  3/4 .181
O8    .521  .25 .303
O9    .632  .25 .095
OH10  .075  .25 .424