K O3.5 U Jove J, Cousson A, Gasperin M Journal of the Less-Common Metals 139 (1988) 345-350 Synthesis and crystal structure of K2 U2 O7 and Mossbauer (237 Np) studies of K2 Np2 O7 and Ca Np O4 _cod_database_code 1001381 _database_code_amcsd 0014163 3.96 3.96 19.82 90 90 120 R-3m atom x y z occ U1 .0443 0 0 .167 K1 0 0 .5 O1 0 0 .0936 O2 .0412 -.064 .3429 .125