Belkovite Choisnet J, Nguyen N, Groult D, Raveau B Materials Research Bulletin 11 (1976) 887-894 De nouveaux oxydes a reseau forme d'octahedres NbO6 (TaO6) et de groupes Si2O7: Les phases A3Ta6Si4O26 (A = Ba,Sr) et K6M6Si4O26 (M = Nb,Ta) Locality: synthetic _database_code_amcsd 0014242 8.981 8.981 7.840 90 90 120 P-62m atom x y z Biso Ba .593 0 .5 0 Nb .238 0 .239 0 Si 1/3 2/3 .203 .25 O1 1/3 2/3 0 .61 O2 .273 0 0 .69 O3 .819 0 .236 .74 O4 .489 .183 .284 .48 O5 .227 0 .5 .68