[CP2K:2872] real time propagation under DDAPC charge constraint

[hut... at pci.uzh.ch]

Hi

as I said, we haven't looked into this. You are of course welcome to explore this further.
What I am concerned of is if the constraint is fulfilled during propagation.

regards

Juerg
-----cp... at googlegroups.com wrote: -----

To: cp... at googlegroups.com
From: Hanning Chen <chenh... at gmail.com>
Sent by: cp... at googlegroups.com
Date: 10/04/2010 06:08PM
Subject: Re: [CP2K:2872] real time propagation under DDAPC charge constraint

Dear Juerg,

  I agree with you that it is not trivial to find a perfect charge constraint strategy. But, I have a feeling that the RT-TDDFT should work under DDAPC constraint. According to the constrained DFT formalism, 

                                      (H0  + Vc * Wc ) * Phi = E * Phi

where Phi is the wavefunction, Vc is the constrain Hartree potential and Wc is the constrain operator. After checking the "cp_ddapc.F" file, the Vc seems to be given in variable "v_hartree_gspace", my question is how to obtain the constrained operator Wc ?

  Once we know both Vc and Wc, we should be able to get the "constrained Hamiltonian", under which the wavefunction only has a stationary phase shift upon time evolution, becasue Phi is now the eigenstate of ( H0 + Vc * Wc). I believe It is a rigorous way to check whether the constrained wavefunction is well converged. 

  Thanks.

Hanning



On Mon, Oct 4, 2010 at 9:18 AM,  <hut... at pci.uzh.ch> wrote:

Hi


the DDAPC code was not indended/tested to work with RT-TDDFT.

However, we think the DDAPC restraint might work as is, for the

DDAPC constraint we have serious doubts that it is correct.


regards


Juerg


-----cp... at googlegroups.com wrote: -----


To: cp... at googlegroups.com

From: Hanning Chen <chenh... at gmail.com>

Sent by: cp... at googlegroups.com

Date: 10/02/2010 07:29PM

Subject: [CP2K:2868] real time propagation under DDAPC charge constraint


Dear CP2K developers,


  I am trying to run a real-time propagation under DDAPC charge constraint. It seems to me that the following lines of codes in "qs_ks_methods.F" are still executed, and thus update the ks_env%v_hartree_rspace to apply the constraint. Am I right ?



  Thanks.



Hanning



"qs_ks_methods.F"


      ! In case decouple periodic images and/or apply restraints to charges

       IF (do_ddapc) THEN

          CALL qs_ks_ddapc(qs_env, auxbas_pw_pool, rho_tot_gspace, v_hartree_gspace,&


               v_spin_ddapc_rest_r, energy, calculate_forces, ks_env, ks_matrix,    &


               just_energy, ddapc_restraint_is_spin, explicit_potential, error)

       ELSE

          explicit_potential      = .FALSE.


          ddapc_restraint_is_spin = .FALSE.

          IF (.NOT. just_energy) THEN

             CALL pw_transfer(v_hartree_gspace%pw, ks_env%v_hartree_rspace%pw, error=error)

             CALL pw_scale(ks_env%v_hartree_rspace%pw, ks_env%v_hartree_rspace%pw%pw_grid%dvol,&


                  error=error)

          END IF

       END IF






--


You received this message because you are subscribed to the Google Groups "cp2k" group.


To post to this group, send email to cp... at googlegroups.com.


To unsubscribe from this group, send email to cp2k+uns... at googlegroups.com.



For more options, visit this group at http://groups.google.com/group/cp2k?hl=en.







--

You received this message because you are subscribed to the Google Groups "cp2k" group.

To post to this group, send email to cp... at googlegroups.com.

To unsubscribe from this group, send email to cp2k+uns... at googlegroups.com.

For more options, visit this group at http://groups.google.com/group/cp2k?hl=en.







-- 

You received this message because you are subscribed to the Google Groups "cp2k" group.

To post to this group, send email to cp... at googlegroups.com.

To unsubscribe from this group, send email to cp2k+uns... at googlegroups.com.


For more options, visit this group at http://groups.google.com/group/cp2k?hl=en.