# Phosphide iodide

Phosphide iodides or iodide phosphides are compounds containing anions composed of iodide (I$^−$) and phosphide (P$^{3−}$). They can be considered as mixed anion compounds. They are in the category of pnictidehalides. Related compounds include the phosphide chlorides, arsenide iodides antimonide iodides and phosphide bromides.
Phosphorus can form clusters or chains in these compounds, so that some are 1-dimensional or fibrous.
Phosphide iodides are often metallic, black or dark red in colour.

## List

| formula | system | space group | unit cell Å | volume | density | comment |
| [Si$_{40}$P$_6$]I$_{6.5}$ | cubic | Pm3n | a=10.1293 Z=1 | 1039.3 | 3.412 | clathrate |
| K$_4$P$_{21}$I | orthorhombic | Ccmm | a = 12.853; b = 21.795; c = 9.748 Z = 4 | 2730.7 | 2.271 | ruby red;sensitive to air |
| Ca$_2$PI | trigonal | R3m | a=4.30 c=22.17 | | 3.2 | yellow |
| Ca$_3$PI$_3$ | cubic | I4$_1$32 | a=12.31 Z=8 | | 3.78 | colourless |
| Cu$_2$P$_3$I$_2$ | monoclinic | P2$_1$c | a = 15.343, b = 12.925, c = 15.260, β = 116.38°, Z = 16 | | | band gap 0.72 eV; Cu ion conductor |
| Cu$_3$P$_{15}$I$_2$ | monoclinic | P2$_1$/n | a=9.667, b=19.475, c=9.886, β =108.75(2)°, Z=4 | 1762.4 | | grey |
| (CuI)$_3$P$_{12}$ | monoclinic | P2$_1$ | a=12.846 b=13.857 c=9.651 β=109.43 Z=4 | 1620.2 | 3.866 | shiny |
| (CuI)$_2$P$_{14}$ | monoclinic | P2$_1$/c | a = 9.919, b = 9.718, c = 16.478, β = 105.71°, Z = 4 | 1529.0 | 3.539 | |
| (CuI)$_5$P$_{16}$S | | | | | | |
| (CuI)$_3$P$_4$S$_4$ | hexagonal | P6$_3$cm | a=19.082, c=6.691 Z=6 | 2109.9 | | |
| (CuI)$_8$P$_{12}$ | monoclinic | P12$_1$/c1 | a=15.343, b=12.925, c=15.26, β=116.38 | | 4.64 | |
| Ge$_{38}$P$_8$I$_8$ | Cubic | P43n | a=10.507 | | | silvery |
| (CuI)$_5$P$_{16}$Se | | | | | | |
| (CuI)$_2$P$_8$Se$_3$ | | Pbcm | a=9.1348 b=12.351 c=13.873 Z=4 | 1565.2 | 3.673 | red; melt 408 °C; P$_8$Se$_3$ clusters |
| (CuI)$_3$P$_4$Se$_4$ | hexagonal | P6$_3$cm | a = 19.601, c = 6.7196, Z = 6 | | | orange |
| Zn$_3$PI$_3$ | cubic | F42m | a=5.945 | | 4.87 | dark grey; dec 300 °C |
| (ZnI$_2$)$_6$ZnSP$_4$S$_3$ | | | | | | |
| (ZnI$_2$)$_6$ZnSeP$_4$Se$_3$ | cubic | F43c | a=19.542 | 7463.1 | 4.325 | brown |
| Rb$_4$P$_{21}$I | orthorhombic | Ccmm | a = 13.281; b = 21.868; c = 9.771 Z=4 | 2838.1 | 2.619 | dark red |
| Sr$_2$P$_7$I | cubic | P2$_1$3 | a=10.25 | | | dark red; contains heptaphosphanortricyclane |
| Zr$_6$I$_{14}$P | orthorhombic | Cmca | | | | |
| Ag$_2$P$_3$I$_2$ | monoclinic | | | | | Ag ion conductor |
| (AgI)$_2$Ag$_3$PS$_4$ | hexagonal | P6$_3$mc | a=7.395 c=12.224 Z=2 | 579.1 | | Ag ion conductor |
| Cd$_2$P$_3$I | monoclinic | C2/c | a=8.255 b=9.304 c=7.514 β =99.66 | | | |
| Cd$_3$PI$_3$ | hexagonal | P6$_3$mc | | | | band gap 2.44 eV |
| Cd$_4$P$_2$I$_3$ | orthorhombic | Pbca | a=12.890 b=12.725 c=12.654 | | | P$_2$$^{4−}$ |
| SnIP | | | | | | soft and flexible; double helix SnI+ and P−; band gap 1.9 eV |
| Sn$_{24}$P$_{19.3}$I$_8$ | cubic | Pm3n | a=10.9554 | | | |
| Sn$_{24}$P$_{19.3}$Br$_x$I$_{8−x}$ | cubic | Pm3n | | | | |
| Sn$_{24}$P$_{19.3(2)}$Cl$_y$I$_{8−y}$ (y ≤ 0.8) | cubic | Pm3n | | | | |
| Sn$_{20}$Zn$_4$P$_{20.8}$I$_8$ | cubic | Pm3n | a=10.883 Z=1 | | | |
| Sn$_{17}$Zn$_7$P$_{22}$I$_8$ | cubic | Pm3n | a=10.8458 Z=1 | | | |
| Sn$_{14}$In$_{10}$P$_{22}$I$_8$ | cubic | Pm3n | a=11.0450 Z=1 | 1347.4 | 5.535 | black |
| Sn$_{14}$In$_{10}$P$_{21.2}$I$_8$ | | P4$_2$/m | a=24.745, c=11.067, Z=5 | 6776 | 5.521 | black |
| [Ge$_{30.5}$Sn$_{7.7}$P$_{7.75}$]I$_{7.88}$ | cubic | Pm3n | a=10.721 Z=1 | | | |
| Sn$_{24}$As$_x$P$_{19.3−x}$I$_8$ | cubic | Pm3n | a = 10.9358—11.1495 | | | |
| Cs$_{0.35}$Zr$_6$I$_{14}$P | orthorhombic | Cmca | a=15.934 b=14.287 c=12.939 Z=4 | | | black |
| Ba$_2$P$_7$I | monoclinic | P2$_1$/m | a=6.3538 b=6.8990 c=12.0392 β =95.515 Z=2 | 524.93 | 3.912 | orange-yellow; water sensitive |
| Ba$_3$P$_3$I$_2$ | orthorhombic | Pnma | a = 17.195, b = 4.624, c = 14.272, Z = 4, | | | |
| Ba$_5$P$_5$I$_3$ | monoclinic | C2/m | a = 42.664, b = 4.56.3, c = 9.431, β = 92.20, Z = 4 | | | |
| La$_2$PI$_2$ | trigonal | P3m1 | a=4.236 c=10.121 Z=1 | 157.25 | 4.95 | |
| Eu$_2$PI | | R3m | a = 4.445, c = 23.12.6, Z = 3 | | | |
| Eu$_2$P$_7$I | cubic | P2$_1$3 | | | | dark red; contains heptaphosphanortricyclane; band gap 1.7 eV |
| Au$_7$P$_{10}$I | trigonal | P31m | a=6.180 c=11.122 Z=1 | | | |
| Hg$_9$P$_5$I$_6$ | monoclinic | | a=13.112 b=12.486 c=17.031 β=119.90 | | | |
| Hg$_4$ZnPI$_4$ | monoclinic | P2$_1$ | a = 7.850, b = 12.719, c = 7.861, β = 119.52°, Z = 2 | | | like Millon phases |
| Hg$_7$Ag$_2$P$_8$I$_6$ | monoclinic | C1$_2$/m1 | a=13.146 b=11.037 c=8.336 β=102.210 Z=2 | 1182.1 | 7.386 | black |
| Hg$_{12}$Ag$_{41}$P$_{88}$I$_{41}$ | cubic | Fm3 | a=26.705 Z=4 | 19045 | 5.147 | dark red; air stable; P$_{11}$$^{3−}$ clusters |
| HgAg$_6$P$_{20}$I$_2$ | monoclinic | P2$_1$/m | a = 6.718, b = 27.701, c = 7.383, β = 113.98°, Z = 2 | | | |