AIM charges problem

Bader charge density analysis

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gopan
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Joined: Tue Dec 12, 2006 3:24 pm

AIM charges problem

Post by gopan »

Hello,

I have a molecule with 16 carbon atoms and 8 sulfur atoms. I wanted to calculate the AIM charges for this molecule.. I have generated the cube file using gaussian utility for the neutral species, and performed the charge computation using the bader (new version).

In my output file (ACF.dat) the total number of electrons amounts to 225.37088, which is wrong as my molecules has only 224 electrons. I am bit confused here, I don't know whether I did something wrong.

thanking you for your help in advance

-gopan
graeme
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Post by graeme »

Do you have an independent way of determining the total charge from the cube file? In principle, this is simply a matter of adding up all the numbers in the file, and possibly normalizing by the voxel size. If you get the same charge that the bader program outputs, the problem is probably due to how the cube file is generated. I would start by seeing how the total charge changes with grid density. The total charge can be very sensitive to resolution in the grid near the atomic centers. If you see the 225.37 number drop closer to 224 when you go to a finer grid, the problem is almost certainly due to the grid resolution.
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