IV
.
D
.3.a. (
XVIII
.
A
.3.)
Species with point groups that differ from experiment at MP2FU/aug-cc-pVTZ
Point group
Species
Name
Experimental
Calculated
C
2
H
4
+
Ethylene cation
D
2h
D
2
ONNO
NO dimer
C
2h
C
2v
SO
3
-
Sulfur trioxide anion
D
3h
C
3v
