Pigeonite Camara F, Carpenter M A, Domeneghetti M C, Tazzoli V Physics and Chemistry of Minerals 29 (2002) 331-340 Non-convergent ordering and displacive phase transition in pigeonite: in situ HT XRD study Sample: hgg, T = 750 C _database_code_amcsd 0008639 Locality: from rhyodacite, Parana, Brazil 9.824 9.017 5.309 90 109.19 90 P2_1/c atom x y z occ Uiso U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) MgM1 .2502 .6530 .2429 .7267 .020 .021 .022 .018 .000 .005 .000 FeM1 .2502 .6530 .2429 .2474 .020 .021 .022 .018 .000 .005 .000 MnM1 .2502 .6530 .2429 .0080 .020 .021 .022 .018 .000 .005 .000 CaM1 .2502 .6530 .2429 .0179 .020 .021 .022 .018 .000 .005 .000 MgM2 .2520 .0187 .2414 .2008 .033 .033 .038 .022 .005 .002 .001 FeM2 .2520 .0187 .2414 .5845 .033 .033 .038 .022 .005 .002 .001 MnM2 .2520 .0187 .2414 .0194 .033 .033 .038 .022 .005 .002 .001 CaM2 .2520 .0187 .2414 .1953 .033 .033 .038 .022 .005 .002 .001 SiA .0439 .3396 .2681 .017 .016 .018 .017 -.002 .006 -.002 SiB .5461 .8385 .2525 .016 .014 .016 .018 -.002 .005 -.001 O1A .8696 .3380 .1587 .021 .012 .027 .021 .001 .003 -.002 O1B .3724 .8393 .1453 .022 .019 .024 .023 .001 .006 .001 O2A .1223 .4960 .3426 .029 .036 .019 .035 -.008 .016 -.003 O2B .6256 .9913 .3597 .032 .031 .030 .036 -.012 .014 -.012 O3A .1019 .2484 .5519 .038 .021 .058 .034 .006 .008 .026 O3B .6034 .7273 .5162 .036 .022 .051 .036 .003 .010 .022