> To be clear, are you asking why MMFF94 is so poor at predicting dipole > moments?
No, he's commenting on a bug. O=C=O clearly should have approximately 0.0D dipole moment. Regardless of the charges on the individual atoms, the charges should cancel in a symmetric molecule. I have no idea the source of the bug, although I can reproduce it. I suspect it's some sort of "race condition" when the molecule is being modified, the dipole moment is not properly updated. I'll take a look later this week. But if you can give me a list of examples for "the dipole moment is totally crazy," I'd appreciate it. As for the accuracy of MMFF94 charges vs. other things, both MMFF94 and Gasteiger give fairly reasonable dipole moments for most organic molecules in my testing. It'd be great to have a more universal charge model, but I don't think one exists at present. It's on my "wish list" in the next year or two to get a charge model which is halfway decent across most elements. -Geoff ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122412 _______________________________________________ Avogadro-Discuss mailing list Avogadro-Discuss@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/avogadro-discuss
