Table 2
(continued)
Stoichiometry
K
l B
m H
n O
(l+3m+n)/
2
Name
Synth T(K)
Space group
Unit cell (Å or deg.)
X-ray T(K)
B-O (Å) ranges
Comments
l
m
n
Tetrahedral
Trigonal
Refs.
Aea2
11.062, 11.175, 9.041
1.474–1.481
1.345–1.380
[B
5 O
6 (OH)
4 ]
−
ions [50]
1
5
4
443
P21
̸ c
9.4824,7.5180,11.4154,
97.277
298
1.457–1.479
1.342–1.399
B
5 O
6 units [42]
1
5
3
473
P1̄
7.5612,9.2236,11.7298,
99.038,106.595,91.314
100
1.468–1.483
1.340–1.396
Condensed B
5 O
6 units [51]
1
5
2
P21
̸ c
7.6690,9.0445,12.2304
119.132
100
1.464–1.482
1.339–1.391
Condensed B5O6 units [52]
1
5
0
α-potassium pentaborate
1033
Pbca
8.52,8.53,21.74
[53]
1033
Pbca
8.383,8.418,21.540
1.469–1.477
1.319–1.405
Condensed B5O6
units [54]
β-potassium pentaborate
973
Pbca
7.42, 11.69,14.72
1.35–1.57
1.07–1.51
[55]
Pbca
7.418,11.702,14.745
1.40–1.49
1.33–1.41
Condensed B5O6
units [56]
114
C. C. Pye