Table 3:
Correlation between point group, site group, and factor group symmetry species and their Raman and IR activities for the
N
O
2
+
and
N
O
3
−
molecular ions in the
N
O
2
+
N
O
3
−
crystal assuming (a)
𝐷
4
6
ℎ
(
𝑃
6
3
/
𝑚
𝑚
𝑐
) and (b)
𝐷
1
7
2
ℎ
(
𝐶
𝑚
𝑐
𝑚
) space group.