E = ½ IAwA2 + ½ IBwB2 + ½ ICwC2
with Ji = Ii · wi (J = kinetic moment) we obtain the following:
E = JA2/(2IA) + JB2/(2IB) + JC2/(2IC)
One can find few formulas for Calculation of
inertia moments here. Now we don't consider the strainless molecules. We
talk about stationary top or stationary rotator contrary to the
moving rotator. We differ the following
four cases:
- Spherical top: | IA = IB = IC = I | CH4, CCl4, SF6 |
- Symmetric top: | IA = IB = I^
and IC = I||
I||> I^ oblate I||< I^ prolate |
Benzene
CH3I |
- Linear top: | IA = 0, IB = IC (all diatomic molecules) | NO, C2N2, CO2 |
- Asymmetric top: | IA ¹ IB ¹
IC, IA ¹
IC
IA < IB < IC |
H2O |