Subject: RE: The PM5 method?

From: "Robinson, James" <[email-masked]>
Date: Fri, 21 Sep 2001 11:05:12 +0100

Does PM5 treat amides and sulphonamides better than AM1 or PM5?

-----Original Message-----
From: David Gallagher [mailto:[email-masked]]
Sent: Tuesday, September 11, 2001 8:41 PM
To: [email-masked]
Subject: CCL:The PM5 method?

Dr James Stewart (author of MOPAC) gave a presentation on PM5 at the Chicago
ACS on August 28, 2001. 

He stated that PM5, now includes ALL main group elements in one method,
adding Li, Be, B, Na, Mg, K, Ca, etc. 

PM5 is also claimed to be significantly more accurate than PM3 or AM1 for
heats of formation. However, the actual improvement in accuracy varies by
element. The average unweighted errors in absolute heats of formation
(kcal/mol) for each method compared to experiment is approximately as shown
below. The averages are based on all elements previously published by
Stewart for PM3 and AM1, and for all main group elements for PM5. Of course,
relative errors are typically much smaller.

AM1       16.4 kcals/mol
PM3       20.4 kcals/mol
PM5        5.6 kcals/mol (preliminary results)

PM5 works with the COSMO solvation field and on systems of up to 20,000
atoms when using the linear scaling option.

Fujitsu is currently testing a beta version of PM5 at present. The PM5
method will be available in CAChe at the end of this month (September), and
also in a new release of MOPAC 2002 in the near future, when more
information should become available.

David Gallagher
Fujitsu ( www.cachesoftware.com/cache5/
<http://www.cachesoftware.com/cache5/> )

At 06:36 AM 9/11/2001 -0700, Mark A. Thompson wrote:

Has the new "PM5" method been described in the literature anywhere?

Mark

http://www.planaria-software.com <http://www.planaria-software.com>