Materials Data on NpAs3 by Materials Project
NpAs3 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Np3+ is bonded to twelve As1- atoms to form a mixture of edge, face, and corner-sharing NpAs12 cuboctahedra. There are four shorter (2.86 Å) and eight longer (3.16 Å) Np–As bond lengths. There are two inequivalent As1- sites. In the first As1- site, As1- is bonded in a 8-coordinate geometry to four equivalent Np3+ and four equivalent As1- atoms. All As–As bond lengths are 2.86 Å. In the second As1- site, As1- is bonded in a square co-planar geometry to four equivalent Np3+ atoms.