# Selenite fluoride

A selenite fluoride is a chemical compound or salt that contains fluoride and selenite anions (F$^−$ and SeO$^{2−}$ $_3$). These are mixed anion compounds. Some have third anions, including nitrate (NO$^−$ $_3$), molybdate (MoO$^{2−}$ $_4$), oxalate (C $_2$O$^{2−}$ $_4$), selenate (SeO$^{2−}$ $_4$), silicate (SiO$^{2−}$ $_4$) and tellurate (TeO$^{2−}$ $_4$).

## Naming

A selenite fluoride compound may also be called a fluoride oxoselenate(IV) using IUPAC naming for inorganic compounds.

## Production

Rare earth selenite fluorides can be produced by dissolving the rare earth selenate into molten lithium fluoride at over 800°C, whereupon the selenate loses oxygen to become selenite, and crystals of the selenite fluoride can form. Another similar method involves heating the rare earth oxide, with a rare earth fluoride and selenium dioxide with a caesium bromide flux. If glass or silica containers are used, they are eaten away by the molten flux and silicates are formed some of which may be fluoride selenite silicate compounds.

## Related

Related to these are the selenite chlorides and selenite bromides by varying the halogenide. Similar compounds by varying the chalcogen also include the sulfite fluorides and tellurite fluorides.

## List

| name | formula | ratio SeO$_3$:F | mw | system | space group | unit cell Å | volume | density | optical |
| scandium selenite fluoride | ScSeO$_3$F | 1:1 | | triclinic | P1 <13 | −173°C a=6.2769 b=6.5578 c=4.0627 α=95.478 β=95.332 γ=92.363 Z=2 | | 3.830 | |
| scandium selenite fluoride | ScSeO$_3$F | 1:1 | | monoclinic | P2$_1$/m >13 | a=4.0643 b =6.6109 c=6.32.35 β=93.298° Z=2 | | | |
| | Na$_3$Ti$_3$O$_3$(SeO$_3$)$_4$F | 4:1 | | hexagonal | P6$_3$ | a =12.8439 c =5.2339 | | | SHG 6 × KDP |
| dimanganese difluoride selenite | Mn$_2$SeO$_3$F$_2$ | 1:2 | 274.83 | orthorhombic | Pnma | a = 7.50848 b = 10.350 and c = 5.47697 Z=4 | | | pink |
| ferric difluoride selenite | FeSeO$_3$F | 1:1 | 201.81 | monoclinic | P2$_1$/n | a=4.9559 b=5.2023 c=12.040 β=97.87 Z=4 | 307.50 | 4.359 | yellow |
| ammonium diferric trifluoride diselenite | NH$_4$Fe$_2$F$_3$(SeO$_3$)$_2$ | 2:3 | | | | | | | |
| piperizinium | [C$_4$N$_2$H$_{12}$]Fe$_4$F$_6$(SeO$_3$)$_4$ | 2:3 | 933.40 | monoclinic | C2/c | a=15.168 b=7.3973 c=16.127 β=90.044 Z=5 | 1928.9 | 3.14 | brown |
| diethylenetriamine | [C$_4$N$_3$H$_{14}$]Fe$_4$F$_6$(SeO$_3$)$_4$ | 2:3 | | | | | | | |
| dicobalt difluoride selenite | Co$_2$SeO$_3$F$_2$ | 1:2 | 282.82 | orthorhombic | Pnma | a = 7.2655 b = 10.001 c = 5.3564 Z=4 | 389.22 | 4.826 | pink |
| | Ni$_2$(SeO$_3$)F$_2$ | 1:2 | 282.3 | orthorhombic | Pnma | a=7.1727 b=9.9377 c=5.2364 | 373.25 | | yellow |
| dicopper difluoride selenite | Cu$_2$(SeO$_3$)F$_2$ | 1:2 | 292.05 | orthorhombic | Pnma | a = 7.066 b = 9.590 c = 5.563 Z=4 | 377.0 | 5.146 | light green |
| dizinc difluoride selenite | Zn$_2$(SeO$_3$)F$_2$ | 1:2 | 295.70 | orthorhombic | Pnma | a=7.276 b=10.042 c=5.256 Z=4 | 384.0 | 5.114 | colourless |
| triethylenediamin-di-ium digallium hexafluoride selenite | C$_6$H$_{14}$N$_2$Ga$_2$F$_6$SeO$_3$ | 1:6 | 494.59 | Monoclinic | P2$_1$/c | a=12.616 b=7.2700 c=13.605 β=104.746 Z=4 | 1206.8 | 2.722 | colourless |
| ethelenediamin-di-ium gallium trifluoride selenite | C$_2$H$_{10}$N$_2$GaF$_3$SeO$_3$ | 1:3 | 315.80 | monoclinic | P2$_1$/c | a=9.1107 b=8.0382 c=10.8302 β=90.045 Z=4 | 793.1 | 2.2355 | colourless |
| piperizin-di-ium gallium fluoride oxalate selenite hydrate | H$_2$pipGaFSeO$_3$[C$_2$O$_4$]H$_2$O | 1:1 | 409.87 | triclinic | P1 | a=6.377 b=9.2820 c=11.4112 α=66.53 β=77.44 γ=71.89 | 585.47 | 2.325 | colourless |
| | (C$_4$H$_{15}$N$_3$)$_2$Ga$_4$F$_2$(SeO$_3$)$_6$(C$_2$O$_4$).4H$_2$O | 6:2 | 1467.11 | triclinic | P1 | a=8.9941 b=9.4963 c=11.2959 α=77.13 β=68.073 γ=83.776 Z=1 | 872.17 | 2.793 | colourless |
| | Sr(VO$_2$F)(SeO$_3$) | | 316.52 | orthorhombic | Pbca | a=9.7816 b=8.0278 c=12.927 Z=8 | 1015.07 | 4.142 | yellow |
| yttrium selenite fluoride | YSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c <319 | a=6.5765 b=6.8971 c=7.1728 β=99.036 Z=4 | | | |
| yttrium selenite fluoride | YSeO$_3$F | 1:1 | | monoclinc | P 2$_1$/m >319 | 600° a=6.5840 b=6.9809 c=4.3434 β =95.032 Z=2 | | 3.922 | |
| | Ag$_3$Ti$_3$O$_3$(SeO$_3$)$_4$F | | 1042.15 | hexagonal | P6$_3$ | a=12.8975 c=5.2180 Z=2 | 751.70 | 4.604 | colourless SHG 2×KDP |
| | Ag$_2$ZrF$_2$(SeO$_3$)$_2$ | | 598.88 | orthorhombic | Cmca | a=7.3640 b=31.451 c=6.2719 | 1452.6 | 5.477 | colopurless |
| dicadmium difluoride selenite | Cd$_2$(SeO$_3$)F$_2$ | 1:2 | 389.76 | orthorhombic | Pnma | a=7.803 b=10.566 c=5.729 Z=4 | 472.4 | 5.480 | colourless |
| ethelenediamin-di-ium indium trifluoride selenite | C$_2$H$_{10}$N$_2$InF$_3$SeO$_3$ | | 360.90 | monoclinic | P2$_1$/c | a=9.3066 b=8.3012 c=11.2923 Z=4 | 871.68 | 2.750 | colourless |
| caesium triscandium hexafluoride diselenite | CsSc$_3$F$_6$[SeO$_3$]$_2$ | 2:6 | | trigonal | P3m1 | a = 5.6534 c = 10.6987 Z = 1 | | | |
| | Cs(TiOF)$_3$(SeO$_3$)$_2$ | 2:3 | 635.53 | hexagonal | P6$_3$mc | a=7.2420 c=11.8152 Z=2 | 536.65 | 3.933 | Colourless SHG 5xKDP |
| caesium triiron hexafluoride diselenite | CsFe$_3$(SeO$_3$)$_2$F$_6$ | 2:6 | | trigonal | P3m1 | a=5.459 c=10.537 Z=1 | 271.9 | | cyan |
| | Ba(VO$_2$F)(SeO$_3$) | | 366.24 | orthorhombic | Pbca | a=10.0539 b=8.3967 c=13.174 | 1112.18 | 4.375 | yellow |
| lanthanum selenite fluoride | LaSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c | a = 18.198 b = 7.1575 c = 8.464 β = 96.89 Z = 12 | | | |
| cerium selenite fluoride | CeSeO$_3$F | 1:1 | | | | | | | |
| tetrapraseodymium selenate diselenite hexafluoride | Pr$_4$(SeO$_3$)$_2$(SeO$_4$)F$_6$ | 2:6 | | monoclinic | C2/c | a = 22.305 b = 7.1054 c = 8.356 β = 98.05° Z = 4 | | | |
| tripraseodymium fluoride tetraselenite | Pr$_3$F[SeO$_3$]$_4$ | | | | | | | | pale green |
| | Pr$_5$F[SiO$_4$]$_2$[SeO$_3$]$_3$ | 3:1 | | triclinic | P1 | a = 7.0114 b = 9.8268 c = 12.8679 α = 70.552 β = 76.904 γ = 69.417° Z = 2 | | 5.511 | pale green |
| trineodymium fluoride tetraselenite | Nd$_3$(SeO$_3$)$_4$F | | | hexagonal | P6$_3$mc | a=10.515 c=7.1211 | | | |
| trisamarium fluoride tetraselenite | Sm$_3$(SeO$_3$)$_4$F | | | hexagonal | P6$_3$mc | a=10.474 c=7.0224 | | | |
| trigadolinium tetraselenite fluoride | Gd$_3$(SeO$_3$)$_4$F | 4:1 | | hexagonal | P6$_3$mc | a = 10.443 b = 6.9432 Z=2 | | | |
| tridysprosium tetraselenite fluoride | Dy$_3$(SeO$_3$)$_4$F | 4:1 | 1014.34 | hexagonal | P6$_3$mc | a=10.360 c=6.8647 Z=2 | | | |
| holmium selenite fluoride | HoSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c | a=6.5784 b=6.8873 c=7.1825 β =99.213 Z=4 | | 6.43 | |
| | Ho$_3$F[SeO$_3$]$_4$ | 4:1 | | hexagonal | P6$_3$mc | a = 10.3024 c = 6.8037 Z = 2 | | | |
| erbium selenite fluoride | ErSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c | a=6.5553 b=6.8741 c=7.1516 β =99.020 Z=4 | | 6.54 | |
| | Er$_3$F[SiO$_4$][SeO$_3$]$_2$ | 2:1 | | orthorhombic | Pnna | a = 5.8692 b = 15.2931 c = 10.2967 Z = 4 | | | pink |
| thulium selenite fluoride | TmSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c | a=6.5342 b=68607 c=7.1213 β =98,828 Z=4 | | 6.63 | |
| ytterbium selenite fluoride | YbSeO$_3$F | 1:1 | | monoclinic | P2$_1$/c | a=6.5146 b=6.8475 c=7.0924 β =98.637 Z=4 | | 6.77 | |
| Lutetium selenite fluoride | LuF[SeO$_3$] | 1:1 | | monoclinic | P2$_1$/c | −173°C: a=6.4839 b=6.8128 c=7.0581 β=98.657 Z=4 | 308.23 | 6.916 | |
| Lutetium selenite fluoride | LuF[SeO$_3$] | 1:1 | | triclinic | P1 | a=6.4486 b=6.8441 c=4.2798 α=94.063 β=98.657 γ=91.895 Z=2 | 187.04 | 5.698 | |
| Lutetium selenite fluoride | LuF[SeO$_3$] | 1:1 | | monoclinic | P2$_1$/m | 173°C: a=6.4734 b=6.8702 c=4.2843 β=95.602 Z=2 | 189.63 | 5.621 | |
| trilutetium fluoride tetraselenite | Lu$_3$F(SeO$_3$)$_4$ | 4:1 | 1051.75 | trigonal | P6$_3$ | a=9.883 c=7.066 Z=2 | 597.7 | 5.844 | colourless SHG 2.5×KDP |
| | PbVO$_2$(SeO$_3$)F | 1:1 | 436.09 | orthorhombic | Pbca | a=9.812 b=8.147 c=13.026 Z=8 | 1041.3 | 5.563 | yellow |
| cadmium lead fluoride nitrate selenite | PbCdF(SeO$_3$)(NO$_3$) | 1:1 | | orthorhombic | Pca2$_1$ | a=11.121 b=10.366 c=5.3950 Z=4 | 621.9 | 5.634 | SHG 2.6×KDP band gap 4.42 eV |
| bismuth selenite fluoride | BiFSeO$_3$ | 1:1 | 354.94 | orthorhombic | Pca2$_1$ | a=6.6774 b=6.8872 c=7.4702 Z=4 | 343.54 | 6.862 | colourless SHG 13.5×KDP |
| tribismuth triselenite pyroselenite fluoride | Bi$_3$(SeO$_3$)$_3$(Se$_2$O$_5$)F | 3:1 | | monoclinic | F21 | | | | SHG 3×KDP |
| dibismuth potassium pentafluoride selenite | KBi$_2$SeO$_3$F$_5$ | 1:5 | 679.02 | orthorhombic | Pbcm | a=4.553 b=17.80 c=8.80 Z=4 | 712.9 | 6.326 | white band gap 4.08 eV |
| dibismuth rubidium pentafluoride selenite | RbBi$_2$SeO$_3$F$_5$ | 1:5 | 725.39 | Triclinic | P1 | a=8.842 b=8.917 c=9.63 α=88.28 β=89.82 γ=89.76 Z=4 | 758.9 | 6.349 | white band gap 4.18 eV |
| | RbBi(SeO$_3$)F$_2$ | 1:2 | 459.41 | orthorhombic | Pnma | a=13.251 b=6.073 c=6.780 Z=4 | 545.6 | | |
| | Bi$_4$TiO$_2$F$_4$(SeO$_3$)$_4$ | 4:4 | 1499.66 | monoclinic | P2$_1$/c | a=7.0237 b=6.6824 c=17.3240 β=106.637 Z=2 | 779.07 | 6.393 | colourless |
| | Bi$_4$NbO$_3$F$_3$(SeO$_3$)$_4$ | 4:3 | 1541.67 | monoclinic | P2$_1$/c | a=7.0448 b=6.6814 c=17.4051 β=106.931 Z=2 | 783.73 | 6.533 | colourless |
| | Bi$_4$TeO$_4$F$_2$(TeO$_3$)$_2$(SeO$_3$)$_2$ | 2:2 | 1670.64 | monoclinic | P2$_1$/c | a=7.0304 b=6.6782 c=17.355 β=106.155 Z=2 | 782.66 | 7.089 | colourless |
| | Bi$_2$F$_2$(MoO$_4$)(SeO$_3$) | 1:2 | 742.86 | monoclinic | P2$_1$/c | a=7.1005 b=9.660 c=12.972 β=12.091 Z=4 | 753.82 | 6.546 | colourless |
| | Bi$_2$ZrO$_2$F$_2$(SeO$_3$)$_2$ | 2:2 | 833.10 | triclinic | P1 | a=5.8047 b=6.3469 c=6.7419 α=77.665 β=71.365 γ=72.795 Z=1 | 222.87 | 6.207 | colourless |
| | PbBi(SeO$_3$)$_2$F | 2:1 | | orthorhombic | Pca2$_1$ | a=12.9672 b=4.5022 c=11.8221 | | | SHG 10.5×KDP; band gap 3.75 eV |
SHG=second harmonic generator