High temperature tetragonal crystal structure of UPt$_2$Si$_2$

Abstract

High temperature crystal structure of UPt 2 Si 2 determined using single-crystal neutron diffraction at 400 K is reported. It is found that the crystal structure remains of the primitive tetragonal CaBe 2 Ge 2 type with the space group P 4/nmm. Anisotropic displacement factors of the Pt atoms at the 2a (3/4 1/4 0) and Si atoms at the 2c (1/4 1/4 z) Wyckoff sites are found to be anomalously large.