Subject: MOPAC esp error

From: Mario Citra <[email-masked]>
Date: Tue, 3 Jun 97 12:49 EST

I have tried to calculate the electrostatic potential charges on certain
molecules using MOPAC 93.  Although the program works fine for alkanes,
alcohols etc.  It outputs the message " Error from MOPAC:  Program error in
Electrostatic Potential" for certain classes of carbonyls.  This problem has
occured for certain aldehydes and carboxcylic acids, while esters, ketones
and amides give no such error message and calculate the esp charges.  This
error occurs consistantly for ethanoic acid and acetaldehyde but does not
seem to occur as more CH2 groups are added to the molecule.  The problem is
independent of the Hamiltonian employed.  This is probably a bug in MOPAC,
has anyone experienced this problem and know of any fixes?

Regards,
Mario J. Citra  PhD
Syracuse Research Corporation
Merrill Lane
Syracuse, New York 13210-4080

phone 315-426-3462
fax   315-426-3429
email [email-masked]      
Regards,
Mario J. Citra  PhD
Syracuse Research Corporation
Merrill Lane
Syracuse, New York 13210-4080

phone 315-426-3462
fax   315-426-3429
email [email-masked]