Melilite
Smith J V
American Mineralogist 38 (1953) 643-661
Reexamination of the crystal structure of melilite
_database_code_amcsd 0000058
7.789 7.789 5.018 90 90 90 P-42_1m
atom     x     y     z occ
Ca   .3355 .1645 .5073 .85
Na   .3355 .1645 .5073 .10
K    .3355 .1645 .5073 .05
Si   .1396 .3604 .9412
Mg       0     0     0 .50
Al       0     0     0 .40
O1      .5     0 .1804
O2   .1450 .3550 .2583
O3   .0820 .1820 .7909