WebMO - Computational chemistry on the WWW
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December 12, 2019

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Pete Smith
Posted on Tuesday, November 01, 2005 - 7:05 pm:   

I teach at a PUI and use WebMO for instruction almost exclusively. We are planning to upgrade to WebMO Pro 6.x. We currently have Gamess and Mopac installed. What would be the benefits of acquiring some of the other free packages such as NWChem or Tinker?

Any advice would be greatly appreciated.

Kindest regards,
Pete
schmidt
Posted on Tuesday, November 01, 2005 - 7:34 pm:   

For the casual user, NWChem offers much of the same functionality as GAMESS in that they are both 'standard' ab initio packages. The only real addition that I can think of off the top of my head is that you can do coordinate scans in NWChem, but not in GAMESS.

However Tinker is a primarily a molecular mechanics program. This allows you to do simple classical potential energy calculations organic type molecules, with relatively high accuracy (for those system for which the force fields were parameterized). These calculations are very rapid, so large molecules can be optimized, etc. This speed comes at the cost of generality, in that you must assign atom 'types' to each atom, corresponding to a parameterization.
Krishna
Unregistered guest
Posted on Saturday, April 11, 2009 - 1:25 am:   

Hello Schmidt,

Iam interested in calculating HOMO and LUMO levels and potential energy of organic molecules.From your above post i learnt that tinker gives best results for calculating potential energy. Could you please suggest me a good Computational Chemistry software which i can use it for calculating HOMO and LUMO levels.

Regards,
Krishna.
JR Schmidt
Moderator
Username: Schmidt

Post Number: 89
Registered: 11-2006
Posted on Saturday, April 11, 2009 - 10:17 am:   

Any ab initio package will be able to calculate HOMO and LUMO levels. Tinker will give reasonable potential energy curves, but ONLY near the minimum energy structure. Other ab initio packages will give more reasonable energies for more distorted geometries, although calculating bond dissociation energies is very challenging.
krishna
Unregistered guest
Posted on Tuesday, April 14, 2009 - 2:24 am:   

Hai Schmidt,

I really appreciate your help. You are doing a great job.

Thanks a lot,
Krishna.
Anonymous
 
Posted on Thursday, December 06, 2012 - 2:06 am:   

Hello:
I am posting this again because I am not sure the place where I posted the previous message is the right place.

WEBMO PRO is running on a local machine and is not taking up queued jobs on an external server where gaussian is setup. This is true even if there is no other job running on the external server.
The same jobs can be run successfully on the remote server without difficulty.

Job manager shows this.
50 test002 Molecular Energy - Gaussian thenraj webmo 12/6/2012 4:44 Queued (1/1) 0.0 sec
JR Schmidt
Moderator
Username: Schmidt

Post Number: 321
Registered: 11-2006
Posted on Thursday, December 06, 2012 - 10:28 am:   

Two things to try:

1) Look in WebMO error log (the "errors" file in the job directory). You may see some SSH / RSH error messages that are useful.
2) Look into the 'messages' and 'secure' logs on the remote server to see if you see any error messages related to SSH/RSH connections from the WebMO server.
3) You can try deleting/re-adding the remote server. You may see an insightful error message when you re-add the server.

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