Dear Netters! I have a question about the thermal energy, concerning rotational barriers. How can you calculate this energy in dependance of the absolute temperature? Some people told me it must be E = 3/2 * RT for a non-linear molecule, but this does't fit to experimental data (Ethane has a rotational barriere of approx. 3 kcal/mol and 3/2 * RT would be only 0.89 kcal/mol for T=298K). Any suggestions? Kay.