From: Francesco Pietra (chiendarret_at_gmail.com)
Date: Tue Jul 23 2013 - 02:14:14 CDT

Hope not to have missed what seems to be an obvious answer.

FFTK ScanTorsions indicates also dihedrals involving aromatic rings,
such as pyridine and pyrrole, and more exotic ones, like tropylium and
others. Is not that a matter for impropers, forcing those rings to
planarity?

thanks
francesco pietra