While GAFF, MMFF94 and other force fields attempt to replicate heats of formation, the heat for formation of an organic molecule need not always be negative.
(Consider, for example cyclobutane, which is perfectly stable but has a positive DeltaG.) https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/energy1.htm Hope that helps, -Geoff --- Prof. Geoffrey Hutchison Department of Chemistry University of Pittsburgh tel: (412) 648-0492 email: geo...@pitt.edu web: http://hutchison.chem.pitt.edu/ > I've tried for several sets of conformers (X-ray, minimized, 2D), > various input formats (sdf, mol2) and various forcefields and in most > cases I get the positive values of the Total Energy. Is it OK? The trend > is correct (more optimal geometries has lower energies than not optimal > geometries) but still, I would assume to get negative values for good > conformers. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ OpenBabel-discuss mailing list OpenBabel-discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openbabel-discuss
