Ca2Ga2Si(HO4)2 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(15), one O(16), one O(4), one O(7), one O(8), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. In the second Ca site, Ca(2) is bonded to one O(1), one O(10), one O(11), one O(16), one O(2), and one O(7) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. In the third Ca site, Ca(3) is bonded to one O(1), one O(12), one O(16), one O(5), one O(6), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. In the fourth Ca site, Ca(4) is bonded to one O(1), one O(13), one O(14), one O(3), one O(7), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(3)O6 octahedra. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(13), one O(4), and one O(5) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 63-73°. In the second Ga site, Ga(2) is bonded to one O(11), one O(3), one O(6), and one O(8) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-72°. In the third Ga site, Ga(3) is bonded to one O(10), one O(12), one O(14), and one O(8) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-65°. In the fourth Ga site, Ga(4) is bonded to one O(11), one O(12), one O(13), and one O(15) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-64°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(14), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-69°. In the second Si site, Si(2) is bonded to one O(15), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-67°. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(16) atom. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(3), one Ca(4), and one H(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(2), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(4), one Ga(2), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ga(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ga(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ga(2), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(4), and one H(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ca(1), one Ga(2), and one Ga(3) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(3), one Ca(4), and one H(1) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Ca(2), one Ga(1), and one Ga(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(2), one Ga(2), and one Ga(4) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Ca(3), one Ga(3), and one Ga(4) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Ca(4), one Ga(1), and one Ga(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Ca(4), one Ga(3), and one Si(1) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Ca(1), one Ga(4), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(3), and one H(4) atom.
Ca2Ga2Si(HO4)2 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(15), one O(16), one O(4), one O(7), one O(8), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(2)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. The Ca(1)-O(15) bond length is 2.50 Å. The Ca(1)-O(16) bond length is 2.31 Å. The Ca(1)-O(4) bond length is 2.55 Å. The Ca(1)-O(7) bond length is 2.33 Å. The Ca(1)-O(8) bond length is 2.36 Å. The Ca(1)-O(9) bond length is 2.32 Å. In the second Ca site, Ca(2) is bonded to one O(1), one O(10), one O(11), one O(16), one O(2), and one O(7) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(3)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. The Ca(2)-O(1) bond length is 2.34 Å. The Ca(2)-O(10) bond length is 2.36 Å. The Ca(2)-O(11) bond length is 2.38 Å. The Ca(2)-O(16) bond length is 2.34 Å. The Ca(2)-O(2) bond length is 2.67 Å. The Ca(2)-O(7) bond length is 2.31 Å. In the third Ca site, Ca(3) is bonded to one O(1), one O(12), one O(16), one O(5), one O(6), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(4)O6 octahedra. The Ca(3)-O(1) bond length is 2.33 Å. The Ca(3)-O(12) bond length is 2.33 Å. The Ca(3)-O(16) bond length is 2.33 Å. The Ca(3)-O(5) bond length is 2.50 Å. The Ca(3)-O(6) bond length is 2.53 Å. The Ca(3)-O(9) bond length is 2.31 Å. In the fourth Ca site, Ca(4) is bonded to one O(1), one O(13), one O(14), one O(3), one O(7), and one O(9) atom to form CaO6 octahedra that share  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra,  an edgeedge with one Ca(2)O6 octahedra, and  an edgeedge with one Ca(3)O6 octahedra. The Ca(4)-O(1) bond length is 2.30 Å. The Ca(4)-O(13) bond length is 2.37 Å. The Ca(4)-O(14) bond length is 2.49 Å. The Ca(4)-O(3) bond length is 2.59 Å. The Ca(4)-O(7) bond length is 2.34 Å. The Ca(4)-O(9) bond length is 2.33 Å. There are four inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(10), one O(13), one O(4), and one O(5) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 63-73°. The Ga(1)-O(10) bond length is 1.82 Å. The Ga(1)-O(13) bond length is 1.84 Å. The Ga(1)-O(4) bond length is 1.90 Å. The Ga(1)-O(5) bond length is 1.91 Å. In the second Ga site, Ga(2) is bonded to one O(11), one O(3), one O(6), and one O(8) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(3)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-72°. The Ga(2)-O(11) bond length is 1.83 Å. The Ga(2)-O(3) bond length is 1.90 Å. The Ga(2)-O(6) bond length is 1.90 Å. The Ga(2)-O(8) bond length is 1.84 Å. In the third Ga site, Ga(3) is bonded to one O(10), one O(12), one O(14), and one O(8) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-65°. The Ga(3)-O(10) bond length is 1.84 Å. The Ga(3)-O(12) bond length is 1.84 Å. The Ga(3)-O(14) bond length is 1.90 Å. The Ga(3)-O(8) bond length is 1.85 Å. In the fourth Ga site, Ga(4) is bonded to one O(11), one O(12), one O(13), and one O(15) atom to form GaO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-64°. The Ga(4)-O(11) bond length is 1.85 Å. The Ga(4)-O(12) bond length is 1.84 Å. The Ga(4)-O(13) bond length is 1.85 Å. The Ga(4)-O(15) bond length is 1.89 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(14), one O(2), one O(4), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(3)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-69°. The Si(1)-O(14) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.69 Å. The Si(1)-O(4) bond length is 1.65 Å. The Si(1)-O(6) bond length is 1.64 Å. In the second Si site, Si(2) is bonded to one O(15), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra,  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Ca(4)O6 octahedra,  a cornercorner with one Ga(1)O4 tetrahedra,  a cornercorner with one Ga(2)O4 tetrahedra,  a cornercorner with one Ga(4)O4 tetrahedra, and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 62-67°. The Si(2)-O(15) bond length is 1.64 Å. The Si(2)-O(2) bond length is 1.70 Å. The Si(2)-O(3) bond length is 1.65 Å. The Si(2)-O(5) bond length is 1.65 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(9) atom. The H(1)-O(9) bond length is 0.97 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. The H(2)-O(7) bond length is 0.97 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. The H(3)-O(1) bond length is 0.97 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(16) atom. The H(4)-O(16) bond length is 0.97 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(3), one Ca(4), and one H(3) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(2), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(4), one Ga(2), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ca(1), one Ga(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ga(1), and one Si(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ca(3), one Ga(2), and one Si(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(4), and one H(2) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Ca(1), one Ga(2), and one Ga(3) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(3), one Ca(4), and one H(1) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Ca(2), one Ga(1), and one Ga(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(2), one Ga(2), and one Ga(4) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Ca(3), one Ga(3), and one Ga(4) atom. In the thirteenth O site, O(13) is bonded in a trigonal planar geometry to one Ca(4), one Ga(1), and one Ga(4) atom. In the fourteenth O site, O(14) is bonded in a trigonal planar geometry to one Ca(4), one Ga(3), and one Si(1) atom. In the fifteenth O site, O(15) is bonded in a trigonal planar geometry to one Ca(1), one Ga(4), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(3), and one H(4) atom.