Phase-A Kagi H, Parise J B, Cho H, Rossman G R, Loveday J S Physics and Chemistry of Minerals 27 (2000) 225-233 Hydrogen bonding interactions in phase A [Mg7Si2O8(OH)6] at ambient and high pressure Sample: P = 0 GPa _database_code_amcsd 0008404 7.8563 7.8563 9.5642 90 90 120 P6_3 atom x y z Biso Mg1 .3722 .4547 .3857 .78 Mg2 .2252 .2438 .1127 .78 Mg3 1/3 2/3 .1029 .78 Si1 2/3 1/3 .1741 .67 Si2 0 0 .4018 .67 O1 .2001 .0274 -.024 .74 O2 .4766 .0988 .4844 .74 O3 .4538 .2947 .2320 .74 O4 .1704 .4367 .2398 .74 O5 2/3 1/3 0 .74 O6 0 0 .2323 .74 HD1 .455 .161 .405 2.6 HD2 .038 .361 .240 2.6