Re: Semi-empirical codes



1) Has anybody conducted a study regarding the ability of MNDO/AM1/PM3
 to predict dipole moments well?  This might identify atoms/molecules
 that are notoriously bad (such as -NO2), or suggest atoms that might
 be reparameterized (Rzepa with N/AM1, P with others, etc.).  Is
 anybody aware of in-house parameter changes that improve things?
 2) Is there any desire to refit AM1 or PM3 on an atom-by-atom
 basis?  I realize that this would be a lot of work, but if there are
 "known" problems...  When d-orbitals enter into the semi-emp universe,
 this would be a good time to retackle the params, especially since the
 horsepower of machines has staggeringly improved since most of the
 initial work.
 Comments are welcome, especially if "famous" code authors are watching
 the net...
 Joe Leonard
 jle (+ at +) world.std.com
 ---
 Administrivia: This message is automatically appended by the mail exploder.
 CHEMISTRY (+ at +) ccl.net --- everybody; CHEMISTRY-REQUEST (+ at +) ccl.net ---
 coordinator only
 OSCPOST (+ at +) ccl.net : send something from chemistry; FTP: www.ccl.net
 ---