Subject: Re: CCL:The PM5 method?

From: "Mark A. Thompson" <[email-masked]>
Date: Tue, 11 Sep 2001 22:17:27 -0700

Dave,

The results sound intriguing.  However, without a journal publication or description of the method, this information is largely useless to anyone hoping to do research with this method and publish the results.

Is a journal article going to be published?  When?  Where?

Mark

----- Original Message ----- 
  From: David Gallagher 
  To: [email-masked] 
  Sent: Tuesday, September 11, 2001 12:40 PM
  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/)

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

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