Phosphidogermanate

Phosphidogermanates are chemical compounds that have phosphorus bound to germanium to yield anions. They are in the category of phosphidotetrelates and also pnictides. They are analogous to nitridogermanates, phosphidoaluminates, phosphidogallates, phosphidoindates, phosphidosilicates or phosphidostannates.

They are under investigation as infrared non-linear optic materials^[1] and solid-state electrolytes.^[2]

List

formula	MW	crystal system	space group	unit cell Å	volume	density	form	properties	references
GeP		monoclinic	C2/m	a = 15.1948 b = 3.6337 c = 9.1941 β = 101.239°					[3]
Li2GeP2	148.458	tetragonal	I41/acd	a = 12.3069 c = 19.0306 Z=32	2882.42	2.736	Ge4P10 supratetrahedra	red	[4]
LiGe3P3	317.751	orthorhombic	Pbam	a = 9.8459 b = 15.7489 c = 3.5995 Z=4	558.15	3.780	GeP4 and Ge(P3Ge) tetrahedra in 5 and 6-membered rings making 2D slabs	black	[4]
Li8GeP4	252		Pa3	a=11.80203 c=11.80203 Z=8	1643.88	2.037			[5][6]
Li8GeP4	251.99	cubic	P43n	a=11.77294 Z=8	1635.98	2.046			[5][6]
Li14GeP6		cubic	Fm3m	a=5.95667 Z=4		1.860		brown	[2][7]
Li10.1Ge5P			Pnma	a=10.360 b=4.3072 c=24.267 Z=4	1082.8	2.86	Ge5 rings	black; actually is a germanide phosphide	[8]
NaGe3P3		orthorhombic	Pmc21	a=3.6276 b=8.407 c=10.332 Z=2	315.09	3.517	Ge3P7 ring	red; band gap 2.06 eV; semiconductor	[9]
Na2Ge3P3	356.72	monoclinic	C2/m	a = 17.639 b = 3.6176 c = 11.354 β = 92.74° Z=4	723.7	3.274		black	[10]
Na3Ge2P3	307.06	monoclinic	P21/c	a = 7.2894 b = 14.7725 c = 7.0528 β = 106.331° Z=4	728.8	2.798	Ge2P6 with shared P	black	[11]
Na5Ge7P5		monoclinic	C2/m	a = 16.168 b = 3.6776 c = 12.924 β = 91.30° Z=2	768.2	3.343		black	[10]
Na8GeP4	380.4	cubic	Fd3m	a=13.4230 Z=8	2418.53	2.08943	same as Na8SnSb4	black; decomposes over 350°C to Na10Ge2P6;band gap 1.9 eV	[5]
Na10Ge2P6		monoclinic	P21/n	a=13.176 b =7.36.4 c=8.042 β=90.26° Z=2	780.29	2.38		beige; moisture sensitive	[12]
CuGe2P3									[13]
ZnGeP2			I42d	a=5.466 c=10.722				melt 1027°C	[1][14][15][16]
Ag6Ge10P12	1744.76	cubic	I43m	a=10.3111 Z=2	1096.3	5.286		air stable; silver grey; thermoelectric	[17][18][19]
CdGeP2			I42d	a=5.740 c=10.773					[20]
Cs5GeP3		orthorhombic	Pnma	a=14.31 b=5.994 c=15.618 Z=4				metallic	[21]
BaGe2P2	344.46	tetragonal	P42mc	a =7.6153 c =8.490 Z=4	492.3	4.647		light metallic grey; melt 861 °C	[22]