[CPMD-list] Excited geometry optimisation : buggy behaviour when using the SAOP XC potential [CPMD 3.11.1]

[Juerg Hutter]

Hi

I'm very sorry that I myself am not able to help you.
Due to a large teaching load and other administrative
duties I don't have time to look into this problem.
Maybe somebody else will step forward and will commit
some time to this problem.

best regards

Juerg Hutter

----------------------------------------------------------
Juerg Hutter                   Phone : ++41 44 635 4491
Physical Chemistry Institute   FAX   : ++41 44 635 6838
University of Zurich           E-mail: hutter at pci.unizh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
----------------------------------------------------------


On Fri, 24 Nov 2006, Latévi Max LAWSON DAKU wrote:

> Hi,
>
> I've noticed that excited geometry optimisations do not
> work if the SAOP potential is used: at a given step of the
> optimisation process, the  part of the code dealing with
> the solution of the TDA-TDDFT eigenvalue problem stop
> working correctly:
>
>     ================================================================
>     ==            DAVIDSON DIAGONALISATION OF TDDFT MATRIX        ==
>     ================================================================
>      ITER      STATES      SUBSPACE             RESIDUAL        TCPU
>         1           0             2        .00000000E+00        2.59
>         2           0             2        .00000000E+00         .01
>         3           0             2        .00000000E+00         .01
>         4           0             2        .00000000E+00         .01
>         5           0             2        .00000000E+00         .01
>         6           0             2        .00000000E+00         .01
>         7           0             2        .00000000E+00         .01
>    ....
>    ....
>       150           0             2        .00000000E+00         .01
>     >>> RESIDUAL DIIS OPTIMIZATION OF ROOT                         1
>      ITER      ENERGY      SUBSPACE             RESIDUAL        TCPU
>         1         NAN             1                  NAN        1.23
>         2         NAN             2                  NAN        1.24
>    ....
>    ....
>       100        -NAN             1                 -NAN        1.24
>     !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
>     !! DAVIDSON| NOT ALL ROOTS ARE CONVERGED                      !!
>     !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
>     ***     TD_OS| SIZE OF THE PROGRAM IS  135612/ 869600 kBYTES ***
>     LB:-------------------------------------------------------------
>     TD_OS_BERRY|            dE=       NAN eV            f=       NAN
>     TD_OS_BERRY|            x:      -NAN  y:      -NAN  z:      -NAN
>     TD_OS_BERRY|            dE=      -NAN eV            f=      -NAN
>     TD_OS_BERRY|            x:       NAN  y:       NAN  z:       NAN
>     LB:-------------------------------------------------------------
>
>
> I would say that a stack get corrupted, but I do not know the
> internal of the program.
>
> Of course, the nuclear gradients can no more be computed
> and the program stops.
>
> I've set up a simple test-case that helps illustrate what is going
> on. Please see the attached files.
>
>    - "ch3cn.s1_spec.in": input of the excitation calculations
>      that  have to be carried first.
>    - "ch3cn.s1_opt.in": input for performing the excited states
>      calculations.
>
> The files "ch3cn.s1_{spec,opt}.out" are the outputs which I
> have obtained.
>
> For the larger system which I am studying I do not observe this
> behaviour if I remove from the &TDDFT..&END section the statement
> "TD_METHOD_A SAOP" and thus let the program use the PBE
> XC potential. I do need the SAOP potential. Is there a workaround ?
> Are other asymptotically corrected potential implemented in CPMD ?
>
> Thanks in advance.
>
> Regards,
> Max
>
> -- 
> ***********************************************
> Latevi Max LAWSON DAKU
> Departement de chimie physique
> Universite de Geneve - Sciences II
> 30, quai Ernest-Ansermet
> CH-1211 Geneve 4
> Switzerland
>
> Tel: (41) 22/379 6548 ++ Fax: (41) 22/379 6103
> ***********************************************
>
>