Nb2Pb3N4 crystallizes in the orthorhombic Pnna space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted NbN4 trigonal pyramids that share corners with two equivalent Pb(2)N4 trigonal pyramids,  an edgeedge with one Pb(2)N4 trigonal pyramid, and edges with two equivalent Nb(2)N4 trigonal pyramids. In the second Nb site, Nb(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted NbN4 trigonal pyramids that share corners with four equivalent Pb(2)N4 trigonal pyramids and edges with two equivalent Nb(1)N4 trigonal pyramids. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2) atoms. In the second Pb site, Pb(2) is bonded to four equivalent N(1) atoms to form distorted PbN4 trigonal pyramids that share corners with two equivalent Nb(1)N4 trigonal pyramids, corners with four equivalent Nb(2)N4 trigonal pyramids,  an edgeedge with one Nb(1)N4 trigonal pyramid, and edges with two equivalent Pb(2)N4 trigonal pyramids. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted rectangular see-saw-like geometry to one Nb(1), one Nb(2), and two equivalent Pb(2) atoms. In the second N site, N(2) is bonded to one Nb(1), one Nb(2), and two equivalent Pb(1) atoms to form distorted corner-sharing NNb2Pb2 trigonal pyramids.
Nb2Pb3N4 crystallizes in the orthorhombic Pnna space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted NbN4 trigonal pyramids that share corners with two equivalent Pb(2)N4 trigonal pyramids,  an edgeedge with one Pb(2)N4 trigonal pyramid, and edges with two equivalent Nb(2)N4 trigonal pyramids. Both Nb(1)-N(1) bond lengths are 1.97 Å. Both Nb(1)-N(2) bond lengths are 2.03 Å. In the second Nb site, Nb(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted NbN4 trigonal pyramids that share corners with four equivalent Pb(2)N4 trigonal pyramids and edges with two equivalent Nb(1)N4 trigonal pyramids. Both Nb(2)-N(1) bond lengths are 2.14 Å. Both Nb(2)-N(2) bond lengths are 1.94 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2) atoms. There is one shorter (2.52 Å) and one longer (2.56 Å) Pb(1)-N(2) bond length. In the second Pb site, Pb(2) is bonded to four equivalent N(1) atoms to form distorted PbN4 trigonal pyramids that share corners with two equivalent Nb(1)N4 trigonal pyramids, corners with four equivalent Nb(2)N4 trigonal pyramids,  an edgeedge with one Nb(1)N4 trigonal pyramid, and edges with two equivalent Pb(2)N4 trigonal pyramids. There are two shorter (2.55 Å) and two longer (2.71 Å) Pb(2)-N(1) bond lengths. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted rectangular see-saw-like geometry to one Nb(1), one Nb(2), and two equivalent Pb(2) atoms. In the second N site, N(2) is bonded to one Nb(1), one Nb(2), and two equivalent Pb(1) atoms to form distorted corner-sharing NNb2Pb2 trigonal pyramids.