From owner-chemistry@ccl.net Sat Apr 25 14:44:01 2009
From: "David Eisenberg david.eisen]~[gmail.com" <owner-chemistry(a)server.ccl.net>
To: CCL
Subject: CCL: Too many resonance structures in NRT
Message-Id: <-39163-090425144304-10771-0liNHFWZWizZ2h0eC3Biwg(a)server.ccl.net>
X-Original-From: "David  Eisenberg" <david.eisen,gmail.com>
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