Materials Data on Np(SiAu)2 by Materials Project

Abstract

Np(AuSi)2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np7+ is bonded to eight equivalent Si4- atoms to form NpSi8 hexagonal bipyramids that share corners with sixteen equivalent AuSi4 tetrahedra, edges with four equivalent NpSi8 hexagonal bipyramids, edges with eight equivalent AuSi4 tetrahedra, and faces with four equivalent NpSi8 hexagonal bipyramids. All Np–Si bond lengths are 3.18 Å. Au+0.50+ is bonded to four equivalent Si4- atoms to form AuSi4 tetrahedra that share corners with eight equivalent NpSi8 hexagonal bipyramids, corners with four equivalent AuSi4 tetrahedra, edges with four equivalent NpSi8 hexagonal bipyramids, and edges with four equivalent AuSi4 tetrahedra. All Au–Si bond lengths are 2.57 Å. Si4- is bonded in a 9-coordinate geometry to four equivalent Np7+, four equivalent Au+0.50+, and one Si4- atom. The Si–Si bond length is 2.27 Å.