The crystal structure of LaPtInH0.53

Abstract LaPtIn was attempted hydrogenated at a hydrogen pressure of 182 bar and temperatures from room temperature to 673 K. The crystal structure of the resulting LaPtInH 0.53 hydride was determined from powder neutron diffraction data. The structure was indexed on an expanded LaPtIn intermetallic unit cell with space group P 6 ¯ 2 m and dimensions a  = 7.8229(2) A and c  = 4.1647(2) A. Hydrogen occupies tetrahedral 4h sites in such a way that tetrahedral voids sharing a common face are not simultaneously populated. The result could not support previous density-functional theory calculations regarding the hydrogen absorption capacity of LaPtIn [P. Ravindran, P. Vajeeston, R. Vidya, A. Kjekshus, H. Fjellvag, Phys. Rev. Lett. 89 (2002) 106403].