Materials Data on NpB4 by Materials Project

NpB4 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Np6+ is bonded in a 12-coordinate geometry to eighteen B+1.50- atoms. There are a spread of Np–B bond distances ranging from 2.70–3.00 Å. There are three inequivalent B+1.50- sites. In the first B+1.50- site, B+1.50- is bonded in a distorted trigonal planar geometry to six equivalent Np6+ and three B+1.50- atoms. There is two shorter (1.69 Å) and one longer (1.74 Å) B–B bond length. In the second B+1.50- site, B+1.50- is bonded in a 1-coordinate geometry to four equivalent Np6+ and five B+1.50- atoms. There is one shorter (1.60 Å) and four longer (1.76 Å) B–B bond length. In the third B+1.50- site, B+1.50- is bonded in a 9-coordinate geometry to four equivalent Np6+ and five B+1.50- atoms. Both B–B bond lengths are 1.82 Å.