| 1:05:58 PM PDT - Mon, Jun 29th 2015 |
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In a standard calculation it is not possible to directly specify the total charge of a single atom in a molecule (note this is not a limitation of the code, just a consequence of the quantum nature of electrons).
If you are interested in modifying the nuclear charge of an atom, this is most easily accomplished in the geometry block. For example,
Oi -0.54181487 0.29839834 -0.75904939 charge 7
would set the nuclear charge of your interstitial oxygen atom to 7. You would then use the charge directive to set the total charge of the whole system to fix the number of electrons in the system.
If you want to calculate the system with a specific total charge for the interstitial atom, then you would need to use the constrained DFT formalism (http://nwchemgit.github.io/index.php/Release65:Density_Functional_Theory_for_Molecules#CDFT_...).
Best,
Sean
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