Hillebrandite Dai Y S, Post J E American Mineralogist 80 (1995) 841-844 Crystal structure of hillebrandite: A natural analogue of calcium silicate hydrate (CSH) phases in Portland cement _database_code_amcsd 0001745 3.6389 16.311 11.829 90 90 90 Cmc2_1 atom x y z occ Uiso Ca1 0 .2164 .064 .0137 Ca2 .5 .3992 -.0479 .0114 Ca3 .5 .0490 .1888 .0118 Si1 .430 .0863 -.1019 .5 .011 Si2 .5 .3727 .2134 .5 .008 OH1 0 .3091 -.0812 .014 O2 .5 .1259 .0198 .013 O3 .5 .4637 .138 .024 O4 .5 .2964 .1251 .019 O5 0 .4890 -.1123 .010 OH6 0 .1370 .2361 .013 O7 .364 .1328 -.205 .5 .014 O8 0 .110 -.127 .5 .014