SrCa3Si4 crystallizes in the orthorhombic Pmm2 space group. Sr(1) is bonded in a 7-coordinate geometry to one Si(1), two equivalent Si(2), and four equivalent Si(3) atoms. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one Si(2), two equivalent Si(1), and four equivalent Si(4) atoms. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(4), and four equivalent Si(1) atoms. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one Si(4), two equivalent Si(3), and four equivalent Si(2) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Sr(1), two equivalent Ca(1), four equivalent Ca(2), and two equivalent Si(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sr(1), one Ca(1), four equivalent Ca(3), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Ca(2), two equivalent Ca(3), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Ca(3), two equivalent Ca(2), four equivalent Ca(1), and two equivalent Si(1) atoms.
SrCa3Si4 crystallizes in the orthorhombic Pmm2 space group. Sr(1) is bonded in a 7-coordinate geometry to one Si(1), two equivalent Si(2), and four equivalent Si(3) atoms. The Sr(1)-Si(1) bond length is 3.23 Å. Both Sr(1)-Si(2) bond lengths are 3.30 Å. All Sr(1)-Si(3) bond lengths are 3.17 Å. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one Si(2), two equivalent Si(1), and four equivalent Si(4) atoms. The Ca(1)-Si(2) bond length is 3.12 Å. Both Ca(1)-Si(1) bond lengths are 3.19 Å. All Ca(1)-Si(4) bond lengths are 3.12 Å. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one Si(3), two equivalent Si(4), and four equivalent Si(1) atoms. The Ca(2)-Si(3) bond length is 3.38 Å. Both Ca(2)-Si(4) bond lengths are 3.20 Å. All Ca(2)-Si(1) bond lengths are 3.13 Å. In the third Ca site, Ca(3) is bonded in a 7-coordinate geometry to one Si(4), two equivalent Si(3), and four equivalent Si(2) atoms. The Ca(3)-Si(4) bond length is 3.13 Å. Both Ca(3)-Si(3) bond lengths are 3.17 Å. All Ca(3)-Si(2) bond lengths are 3.12 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Sr(1), two equivalent Ca(1), four equivalent Ca(2), and two equivalent Si(4) atoms. Both Si(1)-Si(4) bond lengths are 2.45 Å. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Sr(1), one Ca(1), four equivalent Ca(3), and two equivalent Si(3) atoms. Both Si(2)-Si(3) bond lengths are 2.45 Å. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to four equivalent Sr(1), one Ca(2), two equivalent Ca(3), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Ca(3), two equivalent Ca(2), four equivalent Ca(1), and two equivalent Si(1) atoms.