Carbon positions in uranium carbides

Abstract

The carbon atom positions in uranium carbides have been determined from neutron diffraction data. UC is face-centered cubic with sodium chloride structure. U/sub 2C/sub 3/ is body-centered cubic with space group 14 bar 3d, and carbon atoms have one parameter of 0.295 with carboncarbon bond distance of 1.295 A. UC/sub 2/ is tetragonal with space group I4/mmm, and the carbon atoms have z parameter of 0.388 with carbon-carbon bond distance of 1.34 A. The metal- carbon bonding is discussed. (auth)