contributions and the difference in the number of conformers in each group (numerical contribution). Since the conformer α2 has the largest p i value in the temperature range from 90 to 350 K as shown in Fig. 3a, at around the inversion
temperature, the numerical advantage of the group β conformers plays a dominant
role in the inversion of the relative abundance.
Fig. 2 Stable geometries of NO
−
3 HNO 3
ð
Þ 2 obtained with MP2/6-31++G** calculations. The
definitions of each group are given in the text. The ΔE ZPE (unit in kcal/mol) means the relative
energy with zero-point vibration correction from the most stable structure α1
Ab Initio Investigations of Stable Geometries …
197
temperature, the numerical advantage of the group β conformers plays a dominant
role in the inversion of the relative abundance.
Fig. 2 Stable geometries of NO
−
3 HNO 3
ð
Þ 2 obtained with MP2/6-31++G** calculations. The
definitions of each group are given in the text. The ΔE ZPE (unit in kcal/mol) means the relative
energy with zero-point vibration correction from the most stable structure α1
Ab Initio Investigations of Stable Geometries …
197