Londonite
Gatta G D, Vignola P, McIntyre G J, Diella V
American Mineralogist 95 (2010) 1467-1472
On the crystal chemistry of londonite [(Cs,K,Rb)Al4Be5B11O28]:
a single-crystal neutron diffraction study at 300 and 20 K
Locality: Antsongombato Gem mine, Betafo district, Madagascar
Note: neutron diffraction study at T = 20 K
_database_code_amcsd 0017718
7.3094 7.3094 7.3094 90 90 90 P-43m
atom      x      y      z occ  Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3)
Cs        0      0      0 .34  .010
K         0      0      0 .34  .010
Rb        0      0      0 .17  .010
Al    .3603  .3603  .3603     .0012
Be1  .24846     .5      0 .12 .0012
B1   .24846     .5      0 .88 .0012
Be2  .74190 .25810 .25810 .97 .0012
B2   .74190 .25810 .25810 .03 .0012
O1   .38070 .61930 .38070     .0012
O2   .36390 .36390 .10010     .0019  .0021  .0021  .0014  .0009  .0004  .0004
O3   .39899 .86510 .13490     .0024  .0023  .0025  .0025 -.0001  .0001  .0002