CCL: MOPAC users



To specify the gradient, use GNORM=0.01, check the manual http://www.openmopac.net/manual/index.html

Both Ghemical and Avogadro are easy-to-use molecular builders, and both will export to mopac format.  Most likely, you will have to be able to open the resulting file in a text editor to do some minor adjustments.  Ghemical will only export the geometry, and you will need to add the keywords by hand.  The GUI in Avogadro allows you to set the values of the most common keywords but not all of them.

Ghemical: http://www.uku.fi/~thassine/projects/ghemical/
Avogadro: http://avogadro.openmolecules.net/wiki/Main_Page

Hope this  helps

Victor

2011/1/9 Olawale Lukman Olasunkanmi waleolasunkanmi ~ gmail.com <owner-chemistry(_)ccl.net>

Sent to CCL by: "Olawale Lukman Olasunkanmi" [waleolasunkanmi|,|http://gmail.com" target="_blank">gmail.com]
Dear all,
I appreciate your earlier contributions while I was getting started.
Please, how do I correct the following errors emanating from or stopping my calculations:
1. the gradient norm is too high for force field calculations
2. the gradient norm is too high, results may be inaccurate
Can you suggest a molecular builder that I can readily download and use to generate my input file?
Thank you in anticipation of your responses.