Dear CCL users
 I have two different conformers of a molecule. I guess that in one of
 them, there are hyperconjugative interactions that stabilize it
 with respect to the other. I have performed NBO analysis and checked the
 donor-acceptor interactions.
  My question is: Is it logical to sum all the donor-acceptor interactions
 and deduce that the one with the higher sum is stabilized more than the
 other by the hyperconjugative interactions. Or should I choose specific
 donor-acceptor interactions among the tabulated in NBO analysis? My worry
 is; in the first case antibond-antibond interactions are also
 considered and in the latter case it is hard to make a wise selection
 among the donor-acceptor interactions.
  I appreciate any comments to my question. Thank you in advance.
  Nurcan Tuzun
  Bogazici University
  Chem Department
  80815 Bebek, Istanbul