Fredrikssonite Burns P C, Cooper M A, Hawthorne F C The Canadian Mineralogist 32 (1994) 397-403 Jahn-Teller-distorted MnO6 octahedra in fredrikssonite, the fourth polymorph of Mg2Mn(BO3)O2 _database_code_amcsd 0005368 9.198 12.528 2.965 90 90 90 Pbam atom x y z occ U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) Mg1 0 0 0 .0057 .0058 .0069 -.0007 0 0 Mg2 .5 0 .5 .92 .0071 .0054 .0075 .0014 0 0 Fe2 .5 0 .5 .08 .0071 .0054 .0075 .0014 0 0 Mg3 .0048 .2800 0 .0062 .0054 .0067 .0009 0 0 Mn4 .74115 .38458 .5 .78 .0044 .0053 .0054 -.0001 0 0 Fe4 .74115 .38458 .5 .20 .0044 .0053 .0054 -.0001 0 0 Al4 .74115 .38458 .5 .02 .0044 .0053 .0054 -.0001 0 0 B .2782 .3598 .5 .0088 .0073 .0027 -.0006 0 0 O1 .8536 .0449 .5 .0065 .0076 .0080 .0015 0 0 O2 .3807 .0786 0 .0069 .0052 .0083 -.0006 0 0 O3 .6277 .1423 .5 .0058 .0061 .0093 .0001 0 0 O4 .1130 .1422 0 .0064 .0070 .0082 .0003 0 0 O5 .8559 .2349 .5 .0065 .0070 .0087 -.0016 0 0