Portlandite Desgranges L, Grebille D, Calvarin g, Chevrier G, Floquet N, Niepce J Acta Crystallographica B49 (1993) 812-817 Hydrogen thermal motion in calcium hydroxide: Ca (O H)2 _cod_database_code 1001769 _database_code_amcsd 0009875 3.589 3.589 4.911 90 90 120 P-3m1 atom x y z U(1,1) U(2,2) U(3,3) U(1,2) U(1,3) U(2,3) O1 1/3 2/3 .7659 .0032 .0032 .0049 .0016 0 0 H1 1/3 2/3 .5715 .0346 .0346 .0107 .0173 0 0 Ca1 0 0 0 .0016 .0016 .0062 .0008 0 0