Materials Data on YUAs2 by Materials Project

Abstract

UYAs2 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. U3+ is bonded to six As3- atoms to form UAs6 octahedra that share corners with six equivalent UAs6 octahedra, edges with four equivalent UAs6 octahedra, and edges with eight equivalent YAs6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.90 Å) and four longer (2.91 Å) U–As bond lengths. Y3+ is bonded to six As3- atoms to form YAs6 octahedra that share corners with six equivalent YAs6 octahedra, edges with four equivalent YAs6 octahedra, and edges with eight equivalent UAs6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.90 Å) and four longer (2.91 Å) Y–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded to two equivalent U3+ and four equivalent Y3+ atoms to form a mixture of edge and corner-sharing AsY4U2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second As3- site, As3- is bonded to four equivalent U3+ and two equivalent Y3+ atoms to form AsY2U4 octahedra that share corners with six equivalent AsY2U4 octahedra and edges with twelve AsY4U2 octahedra. The corner-sharing octahedral tilt angles are 0°.