Bertrandite
Hazen R M, Au A Y
Physics and Chemistry of Minerals 13 (1986) 69-78
High-pressure crystal chemistry of phenakite (Be2SiO4)
and bertrandite (Be4Si2O7(OH)2)
Sample: P = 1 bar
_database_code_amcsd 0007375
8.7135 15.268 4.5683 90 90 90 Cmc2_1
atom     x     y     z Biso B(1,1) B(2,2) B(3,3)  B(1,2) B(1,3) B(2,3)
Be1  .1735 .0527 .1628  .45  .0024  .0005  .0020 -.00005  .0045  .0005
Be2  .3264 .2203 .1517  .48  .0015  .0005  .0058   .0003  .0042 -.0024
Si   .3254 .1144 .6523  .21 .00095 .00026  .0011  .00008  .0005 -.0002
O1   .2897 .1244     0  .38  .0025  .0003  .0018  -.0002 -.0002  .0001
O2   .2101 .0431 .5074  .31  .0016  .0003  .0019  -.0000 -.0009  .0001
O3   .2934 .2093 .5024  .42  .0027  .0003  .0014   .0003 -.0000 -.0001
O4       0 .5852 .5951  .46  .0008  .0005  .0080       0      0 -.0005
OH1      0 .7553 .0886  .54  .0013  .0007  .0066       0      0  .0009
OH2      0 .0872 .0993  .53  .0017  .0008  .0039       0      0  .0008