Cl H4 N O4 Smith H, Levy H Acta Crystallographica 15 (1962) 1201-1206 Neutron Diffraction Study of Ammonium Perchlorate _cod_database_code 1008111 _database_code_amcsd 0016053 9.2 5.82 7.45 90 90 90 Pnma atom x y z N1 .182 .75 .166 Cl1 .432 .25 .193 O1 .314 .25 .061 O2 .570 .25 .107 O3 .418 .053 .303