Calculating the charge difference should include the ghost atoms or not ?

[sungen...@gmail.com]

Hello everyone ,

     I am intending to calculate a charge difference in the adsorption. I have two parts A, B in my systems.

     I could calculate the charge density of A  , B and AB

     in princinple, I can calculate the charge difference with AB-A-B.

     But I have some questions which confuse me a lot,  the first one is on the physical problem, and the 2nd and 3rd are about setting up CP2K.

     1)  when I calculate the charge density of A, should I add B as ghost atoms or not ?

     2) If it should include B as ghost , I should use BSSE section in DFT section  with  this settings  (is this right?). ?

&FORCE_EVAL

  METHOD QS

  &BSSE

   &FRAGMENT

     LIST  ...(for A)

   &END FRAGMENT

   &FRAGMENT

    LIST  ..(for B)

   &END FRAGMENT

   &CONFIGURATION

     GLB_CONF 1 1

     SUB_CONF 1 0 

    &END

   &END BSSE

and 

&FORCE_EVAL

  METHOD QS

  &BSSE

   &FRAGMENT

     LIST  ...(for A)

   &END FRAGMENT

   &FRAGMENT

    LIST  ..(for B)

   &END FRAGMENT

   &CONFIGURATION

     GLB_CONF 1 1

     SUB_CONF 0 1 

    &END

   &END BSSE

     3) I am not quite understand the meaning of the GLB and SUB, what are they used for  ?

Thanks in advance !

      

 

[SRKC Sharma Yamijala]

Dear Sungen,

Based on my experience, for calculating the charge density difference maps, there is no need to add BSSE corrections. This should be only required when you calculate the energy differences. So, to my knowledge, there is no need to perform any further calculations to get the charge density difference maps (If you already got the charge density files of AB, A and B (.cube files)). But, to take the difference, you may need to use the same grid in all the calculations and also need to add the coordinates of B in A.cube file and coordinates A in B.cube file (see the cube files once, you should be able to understand the differences).

HTH,

Sharma.

********************************************************
Chaitanya Sharma,
Prof. Pati's group,
Chemistry and Physics Materials unit,
JNCASR, BANGLORE,
Lab:: (080-2208) 2581, 2809
https://sites.google.com/site/sharmasrkcyamijala/
*********************************************************

On Wed, Apr 8, 2015 at 6:48 PM, <sungen...@gmail.com> wrote:

Hello everyone ,

     I am intending to calculate a charge difference in the adsorption. I have two parts A, B in my systems.

     I could calculate the charge density of A  , B and AB

     in princinple, I can calculate the charge difference with AB-A-B.

     But I have a question which confused me a lot,  the first one is on the physical problem, and the 2nd and 3rd are about setting up CP2K.

     3) I am not quite understand the meaning of the GLB and SUB, what are they useful ?

Thanks in advance !

      

 

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[sungen...@gmail.com]

Sharma, 

     Thanks, that's helpful !

在 2015年4月8日星期三 UTC+8下午9:39:00，Sharma SRK Chaitanya Yamijala写道：