Arsenidosilicates are chemical compounds that contain anions with arsenic bonded to silicon. They are in the category of tetrelarsenides, pnictidosilicates, or tetrelpnictides. They can be classed as Zintl phases or intermetallics. They are analogous to the nitridosilicates, phosphidosilicates, arsenidogermanates, and arsenidostannates. They are distinct from arsenate silicates which have oxygen connected with arsenic and silicon, or arsenatosilicates with arsenate groups sharing oxygen with silicate.
Arsenidosilicates have dark coloured crystals, usually metallic black. They are often decomposed by water, and some are unstable with respect to the water in air.
These compounds have been investigated as ionic conductors, semiconductors and photovoltaics.
List nameformulaformula weightcrystal
systemspace
groupunit cellvolumedensitycommentsrefLi2SiAs2tetragonalI41/acda=12.563 c=19.390red; air sensitive; Si4As10 unitsLiSi3As6orthorhombicCmcaa=14.244 b=11.247 c=10.757water and acid stableLi5SiAs3monoclinicC2/cblack, hydrolysed by waterLi3Si7As8monoclinicP2/ma=8.9904 b=3.7154 c=11.6023 β=96.307 Z=1385.213.52layered; moisture sensitiveNaSi3As3orthorhombica=10.002 b=18.54 c=3.648Li1.5Ga0.9Si3.1As4monoclinicC2/cZ = 8 a = 10.8838 b = 10.8821 c = 13.1591 β=101.9591535.53.979dark greyNa1.36(Si0.86Ga0.14)2As2.98tetragonalI41/aZ = 100? a = 19.8772 c = 37.65214914.93.592dark greyMgSiAs2202.24tetragonalI2da=5.9078 c=10.600 Z=4369.963.63Mg3Si6As8840.33cubicP4332a=11.600 Z=41560.93.58redK2SiAs2orthorhombicIbama=13.132 b=6.999 c=6.340 Z=4golden; explosive decomposition; air sensitive; CAS No=108945-44-4KSi3As3orthorhombicPbama=10.010b=19.139 c=3.664 Z=4purple; 2D frameworkZnSiAs2melt 1096°C; p-type semiconductorSr3Si2As4metallic red; chainsCdSiAs2tetragonalI2da = 5.884 c = 10.882 Z=8Cd7SiAs61264.41cubicP213a=10.9820 Z=41324.56.343blackCs0.16SiAs2water stableCs2SiAs2orthorhombicIbama=7.571 b=14.425 c=6.42water sensitiveCs5SiAs3orthorhombicPnmaa=14.467 b=6.043 c=15.82dark red metallic; air sensitive; planarCs0.11Zn0.05Si0.95As119.39monoclinicC2/ma=35.201 b=3.6649 c=9.9848 β=91.863° Z=241287.43.70blackZrCuSiAstetragonalP4/nmma=3.6736 c=9.5712 Z=2Ba4SiAs4dark metallic; unstable in airBaCuSi2As3orthorhombicPnmaa=13.169 b=10.502 c=4.615thermal insulate, electrical conductorBaGa2Si7As12SHG 2.6 × ZGP; birefringence 0.077BaIn2Si7As12SHG 3.7 × ZGP; birefringence 0.096Ba13Si6Sn8As224551.72tetragonalI2ma = 14.4857, c = 13.5506 Z=22843.45.316black; Si4As10 units; band gap 1.0 eVLaSiAs3orthorhombicPbcaa=6.0855 b=5.9837 c=26.2279 Z=8LaSiAs3orthorhombicPn21aa=6.0498 b=5.9545 c=26.383 Z=8CeSiAs3orthorhombicPn21aa=5.998 b=5.906 c=26.231 Z=8PrSiAs3orthorhombicPn21aa = 5.949, b = 5.877, c = 26.149 Z=8HfCuSiAstetragonalP4/nmma=3.634 c=9.601126.8TaSiAstetragonalP4/nmmIrSi3As3monoclinicCma=6.8476 b=7.47633 c=5.69156 β=118.4270° Z=2256.246.496dark brownish-grey; non-linear optic 1.7× AGS; decompose 1060 °C; band gap 1.5 eVAuSiAsmonoclinicCca=7.2000 b=6.1614 c=6.1646, β =119.135°
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