Johannsenite
Freed R L, Peacor D R
American Mineralogist 52 (1967) 709-720
Refinement of the crystal structure of johannsenite
_database_code_amcsd 0000156
9.978 9.156 5.293 90 105.48 90 C2/c
atom     x     y     z Biso
Ca       0 .6981   .75  .58
Mn       0 .0947   .75  .48
Si   .2129 .4083 .7637  .26
O1   .3797 .4070 .8459  .39
O2   .1368 .2569 .6705  .47
O3   .1518 .4794 .0043  .40