From NWChem
Viewed 384 times, With a total of 2 Posts


9:35:31 PM PDT  Sun, Jul 17th 2011 

I need to assign partial charges to the atoms in my metal and metaloxide clusters in order to develop an MD potential. Of course, these systems can have a large number of degenerate states. Spherical basis sets are of course very helpful in reducing the degeneracy (also setting the number of degenerate states to be zero helps, but causes it's own problems). I know that the manual states that only cartesian basis sets can be used, but the cartesian functions often result in incorrect ground state occupations and energies. Is there any workaround that would enable me to use spherical functions to perform an esp analysis? Is there alternative software that could be utilized such as a bader analysis?
Another problem I have had performing esp analyses (even using cartesian functions) on lowsymmetry systems, I often encounter the error:
Quote:username
carttrans: ld lt lmax 70006
current input line
58: task esp
This type of error is most commonly associatated with calculations not reaching convergence criteria
Another, unrelated question is that to improve convergence of these metal and metal oxide clusters, I would like to try the fragment initial guess but, in certain cases, the restriction that the sum of the multiplicity of the fragments must equal the multiplicity of the molecule is not possible. A case of this situation is a neutral Ni_2 molecule which has a multiplicity of 3, just like the constituent atoms.
is there any way around this?




Bert Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop


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Threads 2
Posts 285


2:26:48 PM PDT  Mon, Jul 18th 2011 

1. Where does it say in the ESP that only cartesian functions can be used?
2. Can you send me an input deck that fails with the lmax error. I think you are going beyond l=5 in angular momemtum. If so, we need to fix the code. Found one place that explicitly sets this to a max of 5.
Bert
Quote: Jul 18th 4:35 amI need to assign partial charges to the atoms in my metal and metaloxide clusters in order to develop an MD potential. Of course, these systems can have a large number of degenerate states. Spherical basis sets are of course very helpful in reducing the degeneracy (also setting the number of degenerate states to be zero helps, but causes it's own problems). I know that the manual states that only cartesian basis sets can be used, but the cartesian functions often result in incorrect ground state occupations and energies. Is there any workaround that would enable me to use spherical functions to perform an esp analysis? Is there alternative software that could be utilized such as a bader analysis?
Another problem I have had performing esp analyses (even using cartesian functions) on lowsymmetry systems, I often encounter the error:
Quote:username
carttrans: ld lt lmax 70006
current input line
58: task esp
This type of error is most commonly associatated with calculations not reaching convergence criteria
Another, unrelated question is that to improve convergence of these metal and metal oxide clusters, I would like to try the fragment initial guess but, in certain cases, the restriction that the sum of the multiplicity of the fragments must equal the multiplicity of the molecule is not possible. A case of this situation is a neutral Ni_2 molecule which has a multiplicity of 3, just like the constituent atoms.
is there any way around this?





9:39:42 AM PDT  Tue, Aug 16th 2011 

ESP module works with spherical basis sets

Thanks so much for fixing the ESP module. It now works with spherical basis sets.



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