Pb5Si2N6 crystallizes in the monoclinic C2/c space group. There are three inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in an L-shaped geometry to two equivalent N(3) atoms. In the second Pb site, Pb(2) is bonded in a water-like geometry to one N(1) and one N(3) atom. In the third Pb site, Pb(3) is bonded in a trigonal non-coplanar geometry to one N(1), one N(2), and one N(3) atom. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form edge-sharing SiN4 tetrahedra. There are three inequivalent N sites. In the first N site, N(2) is bonded in a 3-coordinate geometry to one Pb(3) and two equivalent Si(1) atoms. In the second N site, N(3) is bonded to one Pb(1), one Pb(2), one Pb(3), and one Si(1) atom to form distorted corner-sharing NSiPb3 tetrahedra. In the third N site, N(1) is bonded in a distorted trigonal planar geometry to one Pb(2), one Pb(3), and one Si(1) atom.
Pb5Si2N6 crystallizes in the monoclinic C2/c space group. There are three inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in an L-shaped geometry to two equivalent N(3) atoms. Both Pb(1)-N(3) bond lengths are 2.38 Å. In the second Pb site, Pb(2) is bonded in a water-like geometry to one N(1) and one N(3) atom. The Pb(2)-N(1) bond length is 2.25 Å. The Pb(2)-N(3) bond length is 2.37 Å. In the third Pb site, Pb(3) is bonded in a trigonal non-coplanar geometry to one N(1), one N(2), and one N(3) atom. The Pb(3)-N(1) bond length is 2.33 Å. The Pb(3)-N(2) bond length is 2.37 Å. The Pb(3)-N(3) bond length is 2.40 Å. Si(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form edge-sharing SiN4 tetrahedra. The Si(1)-N(1) bond length is 1.75 Å. The Si(1)-N(3) bond length is 1.76 Å. Both Si(1)-N(2) bond lengths are 1.80 Å. There are three inequivalent N sites. In the first N site, N(2) is bonded in a 3-coordinate geometry to one Pb(3) and two equivalent Si(1) atoms. In the second N site, N(3) is bonded to one Pb(1), one Pb(2), one Pb(3), and one Si(1) atom to form distorted corner-sharing NSiPb3 tetrahedra. In the third N site, N(1) is bonded in a distorted trigonal planar geometry to one Pb(2), one Pb(3), and one Si(1) atom.