CCL: Too many resonance structures in NRT

From: "David Eisenberg" <david.eisen,gmail.com>
Subject: CCL: Too many resonance structures in NRT
Date: Sat, 25 Apr 2009 14:43:00 -0400

 Sent to CCL by: "David  Eisenberg" [david.eisen%gmail.com]
 Dear CCL'ers,
 I'm trying to find the major resonance structures of a rather large
 polycyclic molecule, using the NRT (natural resonance theory) module in NBO
 5.G (with PBE1PBE/6-31G*).
 The job fails because there are more resonance structures than what the
 computer memory can cope with.  I've increased the alloted memory to the
 maximum, and it crashes still.  But I don't need all these structures!  I
 only want to look at the major ones.  Is there a way of increasing the
 threshold, so the program ignores the structures that contribute less than
 so-and-so, and thus saves on memory?  And if it's not possible, any
 suggestions on what I might try to find the major structures anyway?
 Thank you!
 David Eisenberg