Ramsdellite Post J E, Heaney P J American Mineralogist 89 (2004) 969-975 Neutron and synchrotron X-ray diffraction study of the structures and dehydration behaviors of ramsdellite and "groutellite" _database_code_amcsd 0003565 9.2734 2.8638 4.5219 90 90 90 Pnma atom x y z Uiso Mn .1332 .25 .0258 .0021 O1 .9655 .25 .7838 .0041 O2 .2796 .25 .3201 .0034