Chemistry Reference
In-Depth Information
Fig. 6 The Ni
2
In (BaF
2
-HP,
Pnma
) net and some related
structures of oxoacid salts:
Na
2
CO
3
(
C
2/
m
);
b
-Ca
2
SiO
4
(larnite) and isostructural
M
2
SiO
4
,S
2
GeO
4
(
P
2
1
/
n
);
Na
2
SO
4
and
isostructural
M
2
SO
4
(
Cmcm
)
Table 4 Underlying nets in orthoborates
Underlying net
Orthoborate
Correspondence
BO
3
coordination type
T
6
;T
33
;T
42
pcu-b (NaCl)
MBO
3
(M
¼
Al, Ti, V, Cr, Fe,
Sc, In, Bi, La, Ce, Nd, Dy,
Sm, Eu, Yb, Lu)
Normal
T
33
nia (NiAs)
MBO
3
(M
¼
La, Ce, Nd)
Anti
T
6
cor (
a
-Al
2
O
3
)
3
(BO
3
)
2
(M
¼
Ca, Sr, Hg, Eu)
Anti
T
71
K
2
Te
3
M
3
(BO
3
)
2
(M
¼
Mg, Mn, Ni, Cd)
Anti
T
9
gfy (UCl
3
)
Tl
3
BO
3
Anti
T
(12)
sqc
908
Ag
3
BO
3
The low-temperature phase of Ag
2
CO
3
also has the 5,10-coordinated underlying net,
but of the MoSi
2
structure type.
3.1.2 Orthoborates
g
¼
1:1. This is the most numerous group of orthoborates that is topologically
closely related to carbonates. Since all these orthoborates are obtained at a high
temperature and/or pressure, it is not easy to determine which phase is the most
