# Selenogallate

Selenogallates (or selenidogallates) are chemical compounds which contain anionic units of selenium connected to gallium. They can be considered as gallates where selenium substitutes for oxygen. Similar compounds include the thiogallates and selenostannates. They are in the category of chalcogenotrielates or more broadly chalcogenometallates.

## Formation

Selenogallates may be produced by heating a metal azide with gallium monoselenide and selenium in a sealed tube.
Selenogallates containing Se$_2$ units are formed by heating with selenium. Conversely, by heating, extra selenium vapour can be lost forming a compound with less selenium.

## Properties

Most selenogallates are semiconductors. Their resistance drops on exposure to light. Also selenogallates are often coloured, most often red.
Selenogallate structures can include rings such as the four-membered ring: [$_{GaSeGaSe}$] or the five-membered [$_{GaSeSeGaSe}$]. These can be linked into chains.

## Use

Selenogallates are primarily of research interest. They are being researched for photovoltaic cells where efficiencies over 20% are possible, and for photoconductors, and non-linear optical devices.

## List

| name | chem | mw | crystal system | space group | unit cell Å | volume | density | comment |
| | LiGaSe$_2$ | 234.581 | orthorhombic | Pna2$_1$ | a=6.8478 b=8.2575 c=6.5521 Z=4 | 370.5 | 4.206 | band gap 3.39; SHG |
| | [H$_2$dap]$_4$Ga$_4$Se$_{10}$ dap = 1,2-diaminopropane | | monoclinic | C2/c | a 10.821 b 10.820 c 21.386, β 97.265° | | | |
| | [(dienH$_2$)(dienH)$_3$]Ga$_5$Se$_{10}$ dien = diethylenetriamine | | monoclinic | P2$_1$/c | a 6.3116 b 13.748 c 47.890 β 90.640° | | | chain |
| | [(tetaH$_2$)$_3$(teta)]Ga$_6$Se$_{12}$ teta = triethylenetetramine | | monoclinic | Cc | a 20.566 b 25.896 c 12.785 β 125.568° | | | chain |
| | [bappH2][Ga$_2$Se$_4$] bapp =1,4-Bis-(3-aminopropyl)piperazine | 657.63 | triclinic | P1 | a=6.3517 b=7.8498 c=10.7818 α=71.457° β=84.925° γ=72.084° Z=1 | 484.93 | 2.30 | yellow; |
| | [1,3-pdaH$_2$][Ga$_2$Se$_2$(Se$_2$)(Se$_3$)] 1,3-pda = 1,3-diaminopropane | | monoclinic | P2$_1$ | a 7.5724 b 12.3856 c 8.0889 β 94.120° | | | band gap 2.08 eV; GaSeSeSeGaSe & GaSeSeGaSe rings; red |
| | [1,4-bdaH$_2$][Ga$_2$Se$_3$(Se$_2$)] 1,4-bda = 1,4-diaminobutane | | monoclinic | C2/c | a 11.7660 b 11.7743 c 10.9763 β 110.170° | | | band gap 2.32 eV; orange |
| | [Me$_2$NH$_2$]$_2$[Ga$_2$Se$_2$(Se$_2$)$_2$] | | monoclinic | P2$_1$/c | a 14.13 b 8.456 c 14.07 β 100.32° | | | band gap 2.07 eV; red |
| | α-[AEPH]$_2$[Ga$_2$Se$_2$(Se$_2$)$_2$] AEP = N-(2-aminoethyl)piperazine | | monoclinic | Pn | a 6.981 b 15.436 c 11.831 β 91.462° | | | band gap 1.93 eV; red |
| | β-[AEPH]$_2$[Ga$_2$Se$_2$(Se$_2$)$_2$] | | monoclinic | P2$_1$/c | a 10.623 b 16.495 c 7.163 β 94.93° | | | band gap 2.10 eV; red |
| | [Ga(en)$_3$][Ga$_3$Se$_7$(en)] · H$_2$O | 1090.02 | orthorhombic | Pna2$_1$ | a=14.279 b=9.616 c=19.676 Z=4 | 2701.6 | 2.680 | bicyclic Ga$_3$Se$_7$ |
| | NaGaS$_2$ | | monoclinic | C2/c | a 10.226 b 10.227 c 13.506 β 100.926° | 1389.9 | | |
| | NaGaS$_2$•H$_2$O | | monoclinic | C2/c | a=9.5160 b=113986 c=17.8761 β=101.590 | 1899 | | |
| | NaGa$_3$Se$_5$ | 626.95 | orthorhombic | P2$_1$2$_1$2$_1$ | a=9.764 b=13.624 c=27.000 Z=16 | 3591.6 | 4.638 | |
| | KGaSe$_2$ | 266.74 | monoclinic | C2/c | a = 10.878, b = 10.872, c = 15.380, β = 100.18° Z=16 | 1790.3 | 3.959 | air stable; light yellow; mp=965 °C; [Ga$_4$Se$_{10}$]$^{8−}$ units connected into sheets; band gap 2.60 eV |
| | Cr$_{2.37}$Ga$_3$Se$_8$ | | monoclinic | C2/m | | | | magnetic semiconductor; band gap 0.26 eV |
| | MnGa$_2$Se$_4$ | | | | | | | band gap 2.7 eV |
| | [Mn(en)3][Ga2Se5] en = Ethylenediamine | 771.51 | orthorhombic | Pbcn | a=9.772 b=15.297 c=13.749 Z=4 | 2055.2 | 2.50 | red; {[Ga$_2$Se$_5$]$^{2-}$}∞ chains Ga$_2$Se$_2$ and Ga$_2$Se$_3$ rings |
| | [Mn(dap)$_3$]$_{0.5}$GaSe$_2$ | | orthorhombic | Cmcm | a 9.645 b 16.754 c 12.891 | | | |
| | [Mn(atep)]Ga$_2$S$_4$ atep = 4-(2-aminoethyl)triethylenetetramine | | monoclinic | P2$_1$/n | a 9.909 b 11.947 c 14.831, β 102.268° | | | |
| | [Co(en)$_3$]Ga$_2$Se | | orthorhombic | Cmcm | a 9.692 b 15.631 c 12.698 | | | band gap 3.27 eV |
| | {[Ni(tepa)]$_2$SO$_4$}[Ni(tepa)(Ga$_4$S$_6$(SH)$_4$)] tepa = tetraethylenepentamine | | monoclinic | C2/c | a 38.829 b 12.290 c 22.471 β 98.398° | | | |
| cupric selenogallate | CuGaSe$_2$ | 291.186 | tetragonal | | a = 5.5963 c = 11.0036 Z=4 | 344.617 | 5.612 | metallic grey |
| | ZnGa$_2$Se$_4$ | | tetragonal | I42m | | | | |
| | ZnGa$_2$Se$_4$ | | cubic | Fm3m | | | | >15.5GPa |
| | Na$_3$Zn$_2$Ga$_2$Se$_4$ | 519.90 | tetragonal | I4$_1$acd | a 13.481 c 19.26 Z=16 | 3500 | 3.946 | red |
| | Na$_6$Zn$_3$Ga$_2$Se$_9$ | | monoclinic | C2/c | a 16.71 b 16.69 c 13.79 β 101.346° | | | |
| | KZn$_4$Ga$_5$Se$_{12}$ | | | R3 | | | | SHG |
| | LiGaGe$_2$Se$_6$ | 695.60 | orthorhombic | Fdd2 | a 12.5035 b 23.710 c 7.1177 | 2110.1 | 4.336 | brown; band gap 2.64 eV; mp=710 °C |
| | Li$_2$Ga$_2$GeS$_6$ | | orthorhombic | Fdd2 | a=12.0796 b=22.73 c=6.84048 | | | |
| | NaGaGe$_3$Se$_8$ | | monoclinic | P2$_1$/c | a 7.233 b 11.889 c 17.550 β 101.75° | | | |
| | KGaGeSe$_4$ | 497.25 | monoclinic | P2$_1$/c | a=7.3552 b=12.4151 c=17.6213 β =97.026 Z=8 | 1597.02 | 4.136 | yellow |
| | RbGaSe$_2$ | 313.11 | monoclinic | C2/c | a = 10.954, b = 10.949, c = 16.064, β = 99.841° Z=16 | 1898.2 | 4.382 | colourless; mp=930 °C; $_∞$$^2$[Ga$_4$Se$_8$$^{8−}$] layers of supertetrahedra; |
| | RbZn$_4$Ga$_5$Se$_{12}$ | | | R3 | | | | SHG |
| | RbGaGeSe$_4$ | 543.62 | orthorhombic | Pnma | a=17.5750 b=7.4718 c=12.4449 Z=8 | 1634.23 | 4.419 | orange |
| | AgGaSe$_2$ | | tetragonal | I42d | a = 5.9921, c = 10.883 | | 5.71 | transparent from 0.71 to 18 μm; band gap ~1.7 |
| | AgGa$_5$Se$_8$ | | | P42m | a=5.50 c=11.04 | | | band gap 2.1 eV |
| | Ag$_9$GaSe$_6$ | | | P2$_1$3 | | | | band gap 0.56 eV |
| | Ag$_9$GaSe$_6$ | | cubic | F43m | a=11.126 | | | |
| | Li$_x$Ag$_{1–x}$GaSe$_2$ (x = 0.2–0.8) | | tetragonal | I42d | | | | SHG |
| | Na$_{0.45}$Ag$_{0.55}$Ga$_3$Se$_5$ | | trigonal | R32 | a=13.466 c=16.495 Z=12 | 2590.5 | | SHG 1.9 × AGS |
| | KAg$_3$Ga$_8$Se$_{14}$ | 2025.91 | monoclinic | Cm | a 12.8805 b 11.6857 c 9.6600 β 115.998° Z=2 | 1306.87 | 5.148 | orange |
| | AgGaGe$_5$Se$_{12}$ | | | | | | | red; transparent for 0.6–16.5 μm; band gap 2.2 eV |
| | CdGa$_2$Se$_4$ | | tetragonal | I4 | a=5.3167 c=10.2858 Z=2 | | | semiconductor |
| | CdGa$_2$Se$_4$ | | cubic | F43m | a=5.64 Z=4 | | | >21 GPa metallic |
| | CdGa$_2$Se$_4$ | | cubic | Fm3m | a=5.03 Z=4 | | | 4-7.4 GPa |
| | KCd$_4$Ga$_5$Se$_{12}$ | | trigonal | R3 | a 14.362 b 14.362 c 9.724 | | | |
| | RbCd$_4$Ga$_5$Se$_{12}$ | | trigonal | R3 | a 14.4055 b 14.4055 c 9.7688 | | | band gap 2.19 eV; SHG=19×AgGaS$_2$ |
| | InGaSe$_2$ | | tetragonal | I4/mcm | a = 8.051, c = 6.317 Z=4 | | | |
| | SnGa$_4$Se$_7$ | 622.08 | monoclinic | Pc | a=7.269 b=6.361 c=12.408 β =106.556 Z=2 | 549.9 | 3.757 | light yellow;SHG 3.8 × AgGaS$_2$ |
| | KGaSnSe$_4$-cP84 | 543.35 | cubic | Pa3 | a=13.5555 Z=12 | 2490.8 | 4.347 | red |
| | RbGaSnSe$_4$-cP84 | | cubic | Pa3 | a=13.7200 Z=12 | 589.72 | 4.550 | |
| | RbGaSn$_2$Se$_6$ | 866.33 | trigonal | R3 | a=10.4697 c=9.476 Z=3 | 899.5 | 4.798 | deep red |
| | SnGa$_2$GeSe$_6$ | 804.48 | orthorhombic | Fdd2 | a = 47.195, b = 7.521, c = 12.183, Z = 16 | 4324 | 4.943 | red; SHG 1.7 × AgGaS$_2$ |
| | CsGaSe$_2$-mC64 | | monoclinic | C2/c | a = 11.043, b = 11.015, c = 16.810, β = 99.49°, Z = 16 | 2016.7 | | light grey; layers of supertetrahedra $_∞$$^2$[Ga$_4$Se$_8$$^{4–}$]; band gap 3.5 eV |
| | CsGaSe$_2$-mC16 | | monoclinic | C2/c | a = 7.651, b = 12.552, c = 6.170, β = 113.62°, Z = 4 | 542.9 | | over 610 °C; chains $_∞$$^1$[GaSe$_2$$^–$] |
| | CsGaSe$_3$ | | monoclinic | P2$_1$/c | a=7.727, b=13.014, c=6.705, β=106.39°, Z=4 | | | red; chains; band gap 2.25 eV |
| | Cs$_2$Ga$_2$Se$_5$ | 800.07 | monoclinic | C2/c | a = 15.3911, b = 7.3577, c = 12.9219, β = 126.395°, Z = 4 | 1177.89 | 4.51 | yellow; $_∞$$^1$[Ga$_2$Se$_3$(Se$_2$)$^{2–}$] band gap 1.95 eV |
| | Cs$_4$Ga$_6$Se$_{11}$ | | triclinic | P1 | a=9.707 b=9.888 c=16.780 α=76.425° β=77.076° γ=60.876° | 1356.3 | | $_∞$$^1$[Ga6Se$_{11}$]$^{4–}$ |
| | Cs$_6$Ga$_2$Se$_6$ | | monoclinic | P2$_1$/c | a=8.480 b=13.644 c=11.115 β =126.22 Z=2 | | | mp=685 °C; isolated double tetrahedra [Ga$_2$Se$_6$]$^{6−}$ |
| | Cs$_8$Ga$_4$Se$_{10}$ | | triclinic | P1 | a= 7.870 b=9.420 c=11.282 α=103.84° β=93.43° γ=80.88° Z=1 | | 4.42 | tetrameric |
| | Cs$_{10}$Ga$_6$Se$_{14}$ | | monoclinic | C2/m | a=18.233 b=12.889 c=9.668 β=108.20 Z=2 | | 4.39 | hexameric |
| | (Cs$_6$Cl)$_6$Cs$_3$[Ga$_{53}$Se$_{96}$] | 16671.51 | trigonal | R3m | a = 11.990, c = 50.012 Z=1 | 6226.5 | 4.446 | yellow; band gap 2.74 eV |
| | CsZn$_4$Ga$_5$Se$_{12}$ | | trigonal | R3 | | | | |
| | CsGaGeSe$_4$ | 591.06 | orthorhombic | Pnma | a=17.7666 b=7.5171 c=12.6383 Z=8 | 1687.9 | 4.652 | white |
| | Cs$_2$Ge$_3$Ga$_6$Se$_{14}$ | 2007.41 | | P3m1 | a=7.6396 c=13.5866 Z=1 | 686.72 | 4.854 | black |
| | CsAgGa$_2$Se$_4$ | | monoclinic | P2$_1$/c | a=11.225, b=7.944, c=21.303, β=103.10, Z=8 | 1850.3 | | layered |
| | CsCd$_4$Ga$_5$Se$_{12}$ | | trigonal | R3 | a 14.4204 b 14.4204 c 9.7803 | | | band gap 2.21 eV; SHG=16×AgGaS$_2$ |
| | BaGa$_4$Se$_7$ | | monoclinic | Pc | a = 7.625, b = 6.511, c = 14.702, β = 121.24° | | | transparent between 0.47 and 18.0 μm; melts 968 °C; SHG |
| | Ba$_4$Ga$_2$Se$_8$ | 132.48 | monoclinic | P2$_1$/c | a=13.2393 b=6.4305 c=20.6432 β =104.3148 Z=4 | 1702.90 | 5.151 | black air stable; band gap 1.51 eV |
| | Ba$_5$Ga$_2$Se$_8$ | | orthorhombic | Cmca | a 23.433 b 12.461 c 12.214 | | | band gap 2.51 eV |
| | Ba$_5$Ga$_4$Se$_{10}$ | 1755.18 | tetragonal | I4/mcm | a = 8.752, c = 13.971 Z = 2 | 1070.2 | 5.447 | red; bicyclic ring with Ga-Ga bridge; band gap 2.20 eV |
| | Ba$_3$GaSe$_4$Cl | | orthorhombic | Pnma | a 12.691 b 9.870 c 8.716 | | | |
| | Ba$_3$GaSe$_4$Br | | orthorhombic | Pnma | a = 12.8248, b = 9.9608, c = 8.7690 Z = 4 | | | band gap 1.7 eV |
| | LiBa$_4$Ga$_5$Se$_{12}$ | 1852.42 | tetragonal | P42$_1$c | a 13.591 c 6.515 Z=2 | 1203.3 | 5.113 | yellow; band gap 2.44 eV; SHG 1.7×AgGaS$_2$ |
| | NaBaGaSe$_3$ | | orthorhombic | Pnma | a 20.46 b 9.177 c 7.177 | 1347 | | colourless |
| | (Na$_{0.60}$Ba$_{0.70}$)Ga$_2$Se$_4$ | | tetragonal | I4cm | a 7.9549 c 6.2836 | 397.6 | 4.725 | pale yellow |
| | KBa$_3$Ga$_5$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.6341 c 15.644 | 1166.2 | | band gap 2.04 eV; SHG=10×AgGaS$_2$ |
| | MnBa$_4$Ga$_4$Se$_{10}$Cl$_2$ | | tetragonal | I4 | 8.5858 c 15.7739 | | | band gap 2.8 eV; SHG=30×AgGaS$_2$ |
| | FeBa$_4$Ga$_4$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.578 c 15.717 | | | band gap 1.88 eV |
| | CoBa$_4$Ga$_4$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.572 c 15.716 | | | band gap 2.02 eV |
| | Cu$_{0.5}$Ba$_4$Ga$_{4.5}$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.559 c 15.778 | | | band gap 2.6 eV; SHG=39×AgGaS$_2$ |
| | CuBa$_4$Ga$_5$Se$_{12}$ | | | P42$_1$c | a = 13.598, c = 6.527, Z = 2 | | | band gap 1.45 eV; SHG=3×AgGaS$_2$ |
| | ZnBa$_4$Ga$_4$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.561 c 15.757 | | | band gap 3.08 eV; SHG=59×AgGaS$_2$ |
| | Ba$_{10}$Zn$_7$Ga$_6$Se$_{26}$ | | tetragonal | I42m | a 11.2907 c 21.760 Z=2 | 2774.0 | 5.151 | yellow |
| | Ba$_4$Ga$_4$GeSe$_{12}$ | 1848.35 | tetragonal | P42$_1$c | a=13.5468 c=6.4915 Z=2 | 1191.29 | 5.153 | orange yellow; band gap 2.18 eV |
| | BaGa$_2$GeSe$_6$ | | | R3 | | | | |
| | RbBa$_3$Ga$_5$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.6629 c 15.6379 | | | band gap 2.05 eV; SHG=20×AgGaS$_2$ |
| | Ba$_2$GaYSe$_5$ | | triclinic | P1 | a 7.2876Å b 8.6597Å c 9.3876Å, α 103.51° β 103.04° γ 107.43° | | | |
| | Ba$_4$AgGaSe$_6$ | 1199.44 | orthorhombic | Pnma | a=9.1006 b=4.472 c=17.7572 Z=2 | 722.71 | 5.512 | dark red; air stable; band gap 2.50 |
| | Ba$_4$AgGa$_5$Se$_{12}$ | 1953.35 | tetragonal | P42$_1$c | a 13.6544 c 6.5215 Z=2 | 1215.9 | 5.335 | yellow |
| | Ba$_7$AgGa$_5$Se$_{15}$ | | trigonal | P31c | a 10.0467 c 18.689 | | | band gap 2.60 eV |
| | CdBa$_4$Ga$_4$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.611 c 15.805 | | | band gap 3.05 eV; SHG=52×AgGaS$_2$ |
| | Ba$_5$CdGa$_6$Se$_{12}$ | 2401.82 | orthorhombic | Ama2 | a=24.2458 b=19.1582 c=6.6208 Z=4 | 3075.4 | 5.187 | yellow; air stable; band gap 2.60 eV; mp=866 °C |
| | BaGa$_2$SnSe$_6$ | 869.23 | trigonal | R3 | a = 10.145, c = 9.249 Z = 3 | 824.4 | 5.253 | red; SHG 5.2×AgGaS$_2$ |
| | Ba$_4$Ga$_4$SnSe$_{12}$ | 1894.45 | tetragonal | P42$_1$c | a 13.607 c 6.509 Z=2 | 1205.2 | 5.221 | red; band gap 2.16 eV |
| | Ba$_6$Ga$_2$SnSe$_{11}$ | 1950.73 | monoclinic | P2$_1$/c | a 18.715 b 7.109 c 19.165, β 103.29° | 2481.5 | 5.221 | red; bad gap 1.99 eV |
| | Ba$_2$AsGaSe$_5$ | 814.12 | orthorhombic | Pnma | a = 12.632, b = 8.973, c = 9.203, Z = 4 | 1043.1 | 5.184 | black |
| | CsBa$_3$Ga$_5$Se$_{10}$Cl$_2$ | | tetragonal | I4 | a 8.734 c 15.697 | 1197.6 | | band gap 2.08 eV; SHG=100×AgGaS$_2$ |
| | NaLaGa$_4$Se$_8$ | | orthorhombic | Fddd | a 21.1979 b 21.1625 c 12.7216 | | | |
| | La$_3$MnGaSe$_7$ | 1094.11 | hexagonal | P6$_3$ | a 10.5894 c 6.3458 Z=2 | 616.25 | 5.896 | black |
| | La$_3$FeGaSe$_7$ | | hexagonal | P6$_3$ | a=10.5042 c=6.3496 | 606.74 | | |
| | La$_3$CoGaSe$_7$ | | hexagonal | P6$_3$ | a=10.5104 c=6.3708 | 609.48 | | |
| | La$_3$NiGaSe$_7$ | | hexagonal | P6$_3$ | a=10.4826 c=6.3964 | 608.71 | | |
| | La$_3$CuGaSe$_7$ | 1102.71 | hexagonal | P6$_3$ | a=10.626 c=6.392 Z=2 | 626.0 | 5.859 | |
| | La$_3$ZnGaSe$_7$ | 1104.54 | hexagonal | P6$_3$ | a=10.630 c=6.374 Z=2 | 623.7 | 5.881 | |
| | La$_3$Ag$_{0.6}$GaSe$_7$ | | hexagonal | P6$_3$ | a=10.6, c=6.4 Z=2 | | | |
| | La$_3$CdGaSe$_7$ | | hexagonal | P6$_3$ | a=10.606 c=6.380 Z=2 | 621.5 | 6.153 | |
| | Ba$_2$GaLaSe$_5$ | | orthorhombic | Pnma | a 12.5049 b 9.6288 c 8.7355 | | | |
| | NaCeGa$_4$Se$_8$ | | orthorhombic | Fddd | a 21.141 b 21.138 c 12.712 | | | |
| | Ce$_3$CuGaSe$_7$ | 1106.34 | hexagonal | P6$_3$ | a=10.6007 c=6.3775 Z=2 | 620.65 | 5.920 | |
| | Ba$_2$GaCeSe$_5$ | | orthorhombic | Fddd | a 12.494 b 9.599 c 8.738 | | | |
| | Pr$_3$CuGaSe$_7$ | 1108.71 | hexagonal | P6$_3$ | a=10.4181 c=6.3743 Z=2 | 599.16 | 6.146 | |
| | NaNdGa$_4$Se$_8$ | | orthorhombic | Fddd | a 21.015 b 21.045 c 12.709 | | | |
| | Nd$_3$FeGaSe$_7$ | | hexagonal | P6$_3$ | a 10.2453 c 6.4076 Z=2 | 582.47 | | |
| | Nd$_3$CoGaSe$_7$ | | hexagonal | P6$_3$ | a=10.2296 c=6.4272 | 582.47 | | |
| | Nd$_3$NiGaSe$_7$ | | hexagonal | P6$_3$ | a=10.2117 c=6.4066 | 578.57 | | |
| | Nd$_3$CuGaSe$_7$ | 1118.70 | hexagonal | P6$_3$ | a=10.3426 c=6.3869 Z=2 | 591.7 | 6.279 | |
| | Ba$_2$GaNdSe$_5$ | | triclinic | P1 | a 7.29Å b 8.7914Å c 9.47Å, α 103.77° β 102.91° γ 107.72° | | | |
| | SmGa$_2$Se$_4$ | | rhombic | | a=21.34, b=21.60, c=12.74 | | | |
| | Ba$_2$GaSmSe$_5$ | | triclinic | P1 | a 7.3017Å b 8.7635Å c 9.4554Å, α 103.672° β 102.963° γ 107.637° | | | |
| | Gd$_3$FeGaSe$_7$ | | hexagonal | P6$_3$ | a 10.0762 c 6.4265 Z=2 | | | |
| | Ba$_2$GaGdSe$_5$ | | triclinic | P1 | a 7.2834Å b 8.7062Å c 9.4079Å, α 103.65° β 103.02° γ 107.52° | | | |
| | Dy$_3$FeGaSe$_7$ | | hexagonal | P6$_3$ | a 9.9956Å c 6.398 Z=2 | | | |
| | Ba$_2$GaDySe$_5$ | | triclinic | P1 | a 7.2772Å b 8.6543Å c 9.3792Å, α 103.53° β 103.07° γ 107.43° | | | |
| | Ba$_2$GaErErSe$_5$ | | triclinic | P1 | a 7.2721Å b 8.6258Å c 9.3621Å, α 103.41° β 103.13° γ 107.39° | | | |
| | Ba$_2$GaTbSe$_5$ | | triclinic | P1 | a 7.309 b 8.719 c 9.433, α 103.548° β 103.039° γ 107.520° | | | |
| | Ba$_2$GaHoSe$_5$ | | triclinic | P1 | a 7.2964 b 8.670 c 9.406, α 103.482° β 103.049° γ 107.423° | | | |
| | Ba$_2$GaTmSe$_5$ | | triclinic | P1 | a 7.2884 b 8.6376 c 9.3823, α 103.429° β 103.075° γ 107.360° | | | |
| | Ba$_2$GaYbSe$_5$ | | triclinic | P1 | a 7.2864 b 8.6257 c 9.3716, α 103.4154° β 103.0369° γ 107.3396° | | | |
| | Ba$_2$GaLuSe$_5$ | | triclinic | P1 | a 7.2829 b 8.6120 c 9.368, α 103.362° β 103.051° γ 107.308° | | | |
| | HgGa$_2$Se$_4$ | | | | | | | |
| | KHg$_4$Ga$_5$Se$_{12}$ | 2137.58 | trigonal | R3 | a 14.3203 b 14.3203 c 9.7057 Z=3 | 1723.7 | 6.178 | band gap 1.61 eV; SHG=20×AgGaS$_2$ |
| | TlGaSe$_2$ | 432.01 | monoclinic | C2/c | a=10.760 b=10.762 c=15.626 β=100.19 Z=16 | 1780.8 | 6.445 | black; layers of supertetrahedra; mp 804 °C; band gap 1.87 eV |
| | TlGaGeSe$_4$ | 662.52 | orthorhombic | Pnma | a=17.4742 b=7.4105 c=11.9406 Z=8 | 1546.22 | 5.692 | |
| | Tl$_2$Ga$_2$GeSe$_6$ | | tetragonal | I4/mmc | a=8.0770 c=6.2572 Z=4 | | | |
| | Tl$_{0.8}$Ga$_{0.8}$Ge$_{1.2}$Se$_4$-mC112 | 622.22 | monoclinic | C2/c | a=13.5831 b=7.4015 c=30.7410 β =96.066 Z=16 | 3073.3 | 5.379 | red |
| | TlGaSnSe$_4$-mP56 | 701.04 | monoclinic | P2$_1$/c | a=7.501 b=12.175 c=18.203 β =97.164 Z=8 | 1649.4 | 5.646 | red |
| | TlGaSnSe$_4$-cP84 | 708.62 | cubic | Pa3 | a=13.4755 Z=12 | 2447.0 | 5.770 | red |
| | Tl$_2$Ga$_2$SnSe$_6$ | | tetragonal | I4/mmc | a=8.095 c=6.402 Z=4 | | | |
| | TlGaSn$_2$Se$_6$ | | | R3 | a=10.3289 c=9.4340 | 871.64 | 5.6301 | dark grey in bulk; maroon powder |
| | PbGa$_2$Se$_4$ | 662.47 | orthorhombic | Fddd | a =12.73 b=21.26 c=21.55 Z=32 | 5830 | 6.036 | yellow to red; mp 780 °C; band gap 1.83 eV |
| | Pb$_{0.72}$Mn$_{2.84}$Ga$_{2.95}$Se$_8$ | | hexagonal | P6 | a 17.550 c 3.8916 | | | |
| | PbGa$_2$GeSe$_6$ | | orthorhombic | Fdd2 | | | | mp 720 °C biaxial (−) |
| | Pb$_4$Ga$_4$GeSe$_{12}$ | | tetragonal | P42$_1$c | a = 13.064 c = 6.310 Z=2 | | | |
| | Ba$_2$GaBiSe$_5$ | | orthorhombic | Pnma | a=12.691 b=9.190 c=9.245 Z=4 | 1078.2 | 5.841 | yellow |