DOE OSTI2020
Na15W7N19 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are sixteen inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of Na–N bond distances ranging from 2.58–2.95 Å. In the second Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.42–2.84 Å. In the third Na1+ site, Na1+ is bonded to four N3- atoms to form NaN4 tetrahedra that share corners with two equivalent NaN4 tetrahedra, corners with four WN4 tetrahedra, and an edgeedge with one NaN4 trigonal pyramid. There are a spread of Na–N bond distances ranging from 2.48–2.67 Å. In the fourth Na1+ site, Na1+ is bonded to four N3- atoms to form distorted NaN4 trigonal pyramids that share corners with three NaN4 tetrahedra, corners with three WN4 tetrahedra, an edgeedge with one NaN4 tetrahedra, and an edgeedge with one WN4 tetrahedra. There are a spread of Na–N bond distances ranging from 2.37–2.56 Å. In the fifth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.46–2.85 Å. In the sixth Na1+ site, Na1+ is bonded to four N3- atoms to form distorted NaN4 tetrahedra that share corners with two equivalent NaN4 tetrahedra, corners with five WN4 tetrahedra, and a cornercorner with one NaN4 trigonal pyramid. There are a spread of Na–N bond distances ranging from 2.37–2.79 Å. In the seventh Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.42–2.75 Å. In the eighth Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four N3- atoms. There are a spread of Na–N bond distances ranging from 2.34–2.65 Å. In the ninth Na1+ site, Na1+ is bonded to four N3- atoms to form distorted NaN4 tetrahedra that share corners with five WN4 tetrahedra, corners with two equivalent NaN4 trigonal pyramids, and an edgeedge with one NaN4 tetrahedra. There are a spread of Na–N bond distances ranging from 2.35–2.82 Å. In the tenth Na1+ site, Na1+ is bonded in a 3-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.48–3.08 Å. In the eleventh Na1+ site, Na1+ is bonded in a 3-coordinate geometry to three N3- atoms. There are a spread of Na–N bond distances ranging from 2.37–2.65 Å. In the twelfth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.47–3.07 Å. In the thirteenth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.51–2.73 Å. In the fourteenth Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five N3- atoms. There are a spread of Na–N bond distances ranging from 2.48–2.81 Å. In the fifteenth Na1+ site, Na1+ is bonded in a 2-coordinate geometry to four N3- atoms. There are two shorter (2.33 Å) and two longer (2.87 Å) Na–N bond lengths. In the sixteenth Na1+ site, Na1+ is bonded in a distorted linear geometry to six N3- atoms. There are a spread of Na–N bond distances ranging from 2.42–3.12 Å. There are seven inequivalent W6+ sites. In the first W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share a cornercorner with one NaN4 tetrahedra and corners with three WN4 tetrahedra. There are a spread of W–N bond distances ranging from 1.80–1.93 Å. In the second W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share a cornercorner with one NaN4 tetrahedra and corners with three WN4 tetrahedra. There are a spread of W–N bond distances ranging from 1.80–1.93 Å. In the third W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share a cornercorner with one NaN4 tetrahedra, corners with three WN4 tetrahedra, and a cornercorner with one NaN4 trigonal pyramid. There are a spread of W–N bond distances ranging from 1.81–1.93 Å. In the fourth W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share corners with two WN4 tetrahedra, corners with three equivalent NaN4 tetrahedra, and a cornercorner with one NaN4 trigonal pyramid. There are a spread of W–N bond distances ranging from 1.82–1.96 Å. In the fifth W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share a cornercorner with one NaN4 tetrahedra and corners with three WN4 tetrahedra. There are a spread of W–N bond distances ranging from 1.81–1.91 Å. In the sixth W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share corners with two WN4 tetrahedra, corners with four NaN4 tetrahedra, a cornercorner with one NaN4 trigonal pyramid, and an edgeedge with one NaN4 trigonal pyramid. There is two shorter (1.82 Å) and two longer (1.96 Å) W–N bond length. In the seventh W6+ site, W6+ is bonded to four N3- atoms to form WN4 tetrahedra that share corners with two WN4 tetrahedra and corners with three NaN4 tetrahedra. There are a spread of W–N bond distances ranging from 1.83–1.96 Å. There are nineteen inequivalent N3- sites. In the first N3- site, N3- is bonded in a 5-coordinate geometry to four Na1+ and one W6+ atom. In the second N3- site, N3- is bonded in a 6-coordinate geometry to four Na1+ and two W6+ atoms. In the third N3- site, N3- is bonded to four Na1+ and one W6+ atom to form distorted NNa4W trigonal bipyramids that share corners with two NNa4W square pyramids, corners with two NNa4W trigonal bipyramids, a cornercorner with one NNa2W2 trigonal pyramid, and an edgeedge with one NNa4W square pyramid. In the fourth N3- site, N3- is bonded to two Na1+ and two W6+ atoms to form distorted NNa2W2 trigonal pyramids that share a cornercorner with one NNa4W square pyramid, a cornercorner with one NNa4W trigonal bipyramid, and an edgeedge with one NNa3W2 trigonal bipyramid. In the fifth N3- site, N3- is bonded in a 4-coordinate geometry to two Na1+ and two W6+ atoms. In the sixth N3- site, N3- is bonded to four Na1+ and one W6+ atom to form distorted NNa4W square pyramids that share corners with three NNa4W trigonal bipyramids, an edgeedge with one NNa4W square pyramid, and an edgeedge with one NNa3W2 trigonal bipyramid. In the seventh N3- site, N3- is bonded in a 5-coordinate geometry to four Na1+ and one W6+ atom. In the eighth N3- site, N3- is bonded to three Na1+ and two W6+ atoms to form a mixture of distorted edge and corner-sharing NNa3W2 trigonal bipyramids. In the ninth N3- site, N3- is bonded in a 5-coordinate geometry to four Na1+ and one W6+ atom. In the tenth N3- site, N3- is bonded in a 6-coordinate geometry to five Na1+ and one W6+ atom. In the eleventh N3- site, N3- is bonded in a 5-coordinate geometry to three Na1+ and two W6+ atoms. In the twelfth N3- site, N3- is bonded in a 4-coordinate geometry to five Na1+ and one W6+ atom. In the thirteenth N3- site, N3- is bonded to three Na1+ and two W6+ atoms to form distorted NNa3W2 trigonal bipyramids that share corners with two NNa3W2 trigonal bipyramids, edges with two NNa3W2 trigonal bipyramids, and an edgeedge with one NNa2W2 trigonal pyramid. In the fourteenth N3- site, N3- is bonded to three Na1+ and two W6+ atoms to form NNa3W2 trigonal bipyramids that share corners with two NNa3W2 trigonal bipyramids and edges with two NNa4W trigonal bipyramids. In the fifteenth N3- site, N3- is bonded to four Na1+ and one W6+ atom to form distorted NNa4W square pyramids that share corners with three NNa4W trigonal bipyramids, a cornercorner with one NNa2W2 trigonal pyramid, and an edgeedge with one NNa4W trigonal bipyramid. In the sixteenth N3- site, N3- is bonded in a 6-coordinate geometry to four Na1+ and two W6+ atoms. In the seventeenth N3- site, N3- is bonded in a 3-coordinate geometry to two Na1+ and two W6+ atoms. In the eighteenth N3- site, N3- is bonded in a 6-coordinate geometry to five Na1+ and one W6+ atom. In the nineteenth N3- site, N3- is bonded to four Na1+ and one W6+ atom to form distorted NNa4W trigonal bipyramids that share corners with two equivalent NNa4W square pyramids, a cornercorner with one NNa4W trigonal bipyramid, and edges with two NNa3W2 trigonal bipyramids.