La3AgSiS7 crystallizes in the hexagonal P6_3 space group. La(1) is bonded in a 8-coordinate geometry to one S(1), three equivalent S(2), and four equivalent S(3) atoms. Ag(1) is bonded in a trigonal planar geometry to three equivalent S(3) atoms. Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(2) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to three equivalent La(1) and one Si(1) atom to form distorted SLa3Si tetrahedra that share corners with twelve equivalent S(3)La4Ag trigonal bipyramids, corners with six equivalent S(2)La3Si trigonal pyramids, and edges with three equivalent S(2)La3Si trigonal pyramids. In the second S site, S(2) is bonded to three equivalent La(1) and one Si(1) atom to form distorted SLa3Si trigonal pyramids that share corners with two equivalent S(1)La3Si tetrahedra, corners with eight equivalent S(3)La4Ag trigonal bipyramids, corners with four equivalent S(2)La3Si trigonal pyramids,  an edgeedge with one S(1)La3Si tetrahedra, edges with two equivalent S(3)La4Ag trigonal bipyramids, and edges with two equivalent S(2)La3Si trigonal pyramids. In the third S site, S(3) is bonded to four equivalent La(1) and one Ag(1) atom to form distorted SLa4Ag trigonal bipyramids that share corners with four equivalent S(1)La3Si tetrahedra, corners with two equivalent S(3)La4Ag trigonal bipyramids, corners with eight equivalent S(2)La3Si trigonal pyramids, edges with six equivalent S(3)La4Ag trigonal bipyramids, and edges with two equivalent S(2)La3Si trigonal pyramids.
La3AgSiS7 crystallizes in the hexagonal P6_3 space group. La(1) is bonded in a 8-coordinate geometry to one S(1), three equivalent S(2), and four equivalent S(3) atoms. The La(1)-S(1) bond length is 3.15 Å. There are a spread of La(1)-S(2) bond distances ranging from 2.93-3.11 Å. There are a spread of La(1)-S(3) bond distances ranging from 2.97-3.12 Å. Ag(1) is bonded in a trigonal planar geometry to three equivalent S(3) atoms. All Ag(1)-S(3) bond lengths are 2.46 Å. Si(1) is bonded in a tetrahedral geometry to one S(1) and three equivalent S(2) atoms. The Si(1)-S(1) bond length is 2.12 Å. All Si(1)-S(2) bond lengths are 2.15 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to three equivalent La(1) and one Si(1) atom to form distorted SLa3Si tetrahedra that share corners with twelve equivalent S(3)La4Ag trigonal bipyramids, corners with six equivalent S(2)La3Si trigonal pyramids, and edges with three equivalent S(2)La3Si trigonal pyramids. In the second S site, S(2) is bonded to three equivalent La(1) and one Si(1) atom to form distorted SLa3Si trigonal pyramids that share corners with two equivalent S(1)La3Si tetrahedra, corners with eight equivalent S(3)La4Ag trigonal bipyramids, corners with four equivalent S(2)La3Si trigonal pyramids,  an edgeedge with one S(1)La3Si tetrahedra, edges with two equivalent S(3)La4Ag trigonal bipyramids, and edges with two equivalent S(2)La3Si trigonal pyramids. In the third S site, S(3) is bonded to four equivalent La(1) and one Ag(1) atom to form distorted SLa4Ag trigonal bipyramids that share corners with four equivalent S(1)La3Si tetrahedra, corners with two equivalent S(3)La4Ag trigonal bipyramids, corners with eight equivalent S(2)La3Si trigonal pyramids, edges with six equivalent S(3)La4Ag trigonal bipyramids, and edges with two equivalent S(2)La3Si trigonal pyramids.