ROKS input

[Matthias Krack]

Dear Hanning Chen,

the implementation of low-spin ROKS with diagonalization (ROKS_SCHEME
general) is still experimental and largely incomplete. For instance,
the proper summation over the microstates contributing to a multiplet
is missing. By contrast, the high-spin ROKS with diagonalization
should work which is the default. This is why the result of your ROKS
run did not differ from the RKS result. Alternatively, you may check
the LOW_SPIN_ROKS available with OT.

Matthias

On Apr 30, 5:57 am, Hanning Chen <chenh... at gmail.com> wrote:
> Dear CP2k community,
>   I performed geometry optimization for C2H4 at first singlet excited state
> (S1) using ROKS, and found that the optimized geometry is exactly same as
> the ground state (S0). Can anyone help me to figure out the way to optimize
> geometry at low-spin excited state? I also ran an geometry optimization at
> first triplet excited state (T1) , and obtained a distinct geometry as
> expected. I guess I might miss some key options in the input file shown
> below.
>
> Thanks.
>
> Hanning Chen
> Department of Chemistry
> Northwestern University
> Evanston, IL 60208
>
> Input file:
>
>   &FORCE_EVAL
>   METHOD Quickstep
>   &DFT
>     ROKS
>     MULTIPLICITY 1
>     &QS
>       EPS_DEFAULT 1.0E-8
>     &END QS
>     &SCF
>       MAX_SCF 100
>       SCF_GUESS ATOMIC
>       &DIAGONALIZATION
>        ALGORITHM STANDARD
>       &END DIAGONALIZATION
>     &END SCF
>     &XC
>       &XC_FUNCTIONAL PADE
>       &END XC_FUNCTIONAL
>     &END XC
>   &END DFT
>   &SUBSYS
>     &CELL
>       ABC 6.0 6.0 8.0
>     &END CELL
>     &COORD
>     C         -0.2558206925       -0.0439868417        0.6850619693
>     C         -0.2214915625       -0.0386665897       -0.6514432536
>     H         -0.4100752923        0.8714166677        1.2581094627
>     H         -0.1401850725       -0.9650616559        1.2579495323
>     H         -0.0795226532       -0.9560364450       -1.2252531634
>     H         -0.3528336094        0.8817708920       -1.2228724740
>     &END COORD
>         &KIND H
>       BASIS_SET DZVP-GTH-PADE
>       POTENTIAL GTH-PADE-q1
>     &END KIND
>     &KIND C
>       BASIS_SET DZVP-GTH-PADE
>       POTENTIAL GTH-PADE-q4
>     &END KIND
>   &END SUBSYS
> &END FORCE_EVAL
> &GLOBAL
>   PROJECT C2H4
>   RUN_TYPE GEOMETRY_OPTIMIZATION
>   PRINT_LEVEL MEDIUM
> &END GLOBAL