CDFT constain charge for help

Clicked A Few Times

7:39:59 AM PDT - Thu, Apr 10th 2014

HELLO everyone. IN the CDFT model , the example

geometry
symmetry

C  0.0  0.0  0.0

O  1.2  0.0  0.0

C  0.0  0.0  2.0

O  1.2  0.0  2.0

end

cdft 1 2 charge 1.0 

 means put charge 1 in the atom 1 and 2. If I just want to put the charge in the 1 atom, I set

cdft 1 1 charge 1.0 . Is this seting righr or not ? If it is wrong, how to set the charge 1.0 just in the atom 1. Thank you fou help.

Forum Regular

4:19:32 PM PDT - Thu, Apr 10th 2014

Hi Tfliu,

I think your suggestion is right. If this fails (for what ever reason) you can also set

  cdft 2 4 charge -1.0

Further note that if you want to change the total charge of you molecule to +1 then you will also need to add the following charge directive:

  charge +1

in addition to the

  cdft 1 1 charge 1.0

directive.

Huub

Clicked A Few Times

11:13:27 PM PDT - Thu, Apr 10th 2014

Thanks Huub

Thank you very much. The sheme cdft 1 1 charge 1.0 and cdft 2 4 charge -1.0 is the same. But I do not know why cdft 2 4 charge -1.0 can put a charge 1.0 to the atom 1? The two input give the same Lowdin Population Analysis :
Atom Charge Shell Charges

-----------   ------   -------------------------------------------------------

   1 C    6     5.00   1.98  0.46  1.07  0.44  0.48  0.58

   2 O    8     8.66   1.98  0.75  2.87  0.50  1.98  0.58

   3 C    6     6.22   1.98  0.48  1.48  0.60  1.03  0.65

   4 O    8     8.12   1.98  0.75  2.69  0.48  1.68  0.55

But in the spin density, Why there are no single spin?
Spin Density - Lowdin Population Analysis

    ------------------------------------------

   Atom       Charge   Shell Charges

-----------   ------   -------------------------------------------------------

   1 C    6     0.00   0.00  0.00  0.00  0.00  0.00  0.00

   2 O    8     0.00   0.00  0.00  0.00  0.00  0.00  0.00

   3 C    6     0.00   0.00  0.00  0.00  0.00  0.00  0.00

   4 O    8     0.00   0.00  0.00  0.00  0.00  0.00  0.00

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