Geoscience Reference
In-Depth Information
Cell Parameter (
˚
)
Compound
Representative
Rare Earth, Co.
No., Average Bond
Distance (
˚
)
Tetrahedral
Radical Form
Rare Earth Polyhedra
b
5
12.741
c
5
8.441
Na
5
RSi
4
O
12
Na
5
LuSi
4
O
12
R32 z
5
16
Lu
6
2.20
12-Membered
Discrete polyhedra
R
5
Sm
Lu, Y, Sc
a
5
21.926
[4]
ring
c
5
12.556
[2]
LiScSi
2
O
6
C2/cz
5
4
Sc
6
2.107
Chains with period
of 2 tetrahedral
Layer
a
5
9.8033
b
5
8.9581
c
5
5.3512
β
5
110.281
Na
12
Y
4
Si
12
O
36
P2
I
2
I
2
I
z
5
16
Y
6
2.20
Chains with period
of 24 tetrahedral
Discrete polyhedra
a
5
15.033
2
2.36
b
5
15.142
c
5
15.213
NaRSi
6
O
14
NaPrSi
6
O
14
Ibam z
5
8
Pr
6
2.41
Triple layered column
Column
R
5
La
Lu
a
5
7.682
b
5
15.445
c
5
19.724
NaNdSi
6
O
13
Cmm2 z
5
4
Nd
7
2.44
Layers with 8-, 6-, 5-,
and 4-membered
rings
Discrete polyhedra
(OH)
2
nH
2
O
a
5
30.87
(Continued)
