TDDFPT calculation
xujroman
leit... at matcalc.de
Wed Aug 25 08:44:05 UTC 2010
Dear Juerg Hutter,
thank you for your answer.
However, I have found the problem in my cp2k calculation.
I have used the following setting in the DFT-PRINT section.
.
.
.
&PRINT
&MO_CUBES
FILENAME ./MOTEST
STRIDE 1 1 1
NLUMO 1
NHOMO 1
&END MO_CUBES
&MO
EIGENVALUES .TRUE.
OCCUPATION_NUMBERS .TRUE.
&END MO
&END PRINT
.
.
.
This leads to the calculation of only the first unoccupied molecular
orbital. Therefore, I obtained only transitions into this state.
Changing the above section into
.
.
.
&PRINT
&MO_CUBES
WRITE_CUBE .FALSE.
NLUMO 10
&END MO_CUBES
&MO
EIGENVALUES .TRUE.
OCCUPATION_NUMBERS .TRUE.
&END MO
&END PRINT
.
.
.
solved the problem.
However, I found it not intuitive to specify the number of used
unoccupied orbitals of the TDDFT calculation in the section FORCE_EVAL-
> DFT-> PRINT-> MO_CUBES .
Therefore, I suggest for the next cp2k release a new keyword in the
TDDFPT section which specifies the number of LUMOS or at least a hint
in the manual where the number of LUMOS have to be set.
Cheers,
Roman
On Aug 24, 12:56 pm, Juerg Hutter <hut... at pci.uzh.ch> wrote:
> Hi
>
> cp2k uses the Tamm-Dancoff approximation to TDDFT. This is known
> to give excitations that are often very strongly localized (in MO
> space). Do you have evidence that the result you get is not correct?
>
> regards
>
> Juerg
>
> > Dear cp2k users,
>
> > I have tried to to a TDDFT calculation with cp2k.
> > The input file was as follows:
>
> > &FORCE_EVAL
> > METHOD Quickstep
> > STRESS_TENSOR ANALYTICAL
> > &DFT
> > EXCITATIONS tddfpt
> > &TDDFPT
> > MAX_KV 60
> > NEV 8
> > OE_CORR SAOP
> > REORTHO 2
> > RES_ETYPE SINGLETS
> > RESTARTS 5
> > &XC
> > &XC_FUNCTIONAL PBE
> > &END XC_FUNCTIONAL
> > &END XC
> > &END TDDFPT
> > &PRINT
> > &MO_CUBES
> > FILENAME ./MOTEST
> > STRIDE 1 1 1
> > NLUMO 1
> > NHOMO 1
> > &END MO_CUBES
> > &MO
> > EIGENVALUES .TRUE.
> > OCCUPATION_NUMBERS .TRUE.
> > &END MO
> > &END PRINT
> > &POISSON
> > PERIODIC NONE
> > POISSON_SOLVER MULTIPOLE
> > &MULTIPOLE
> > ANALYTICAL_GTERM .TRUE.
> > RCUT 8.0
> > &END MULTIPOLE
> > &END POISSON
> > &MGRID
> > CUTOFF $i
> > REL_CUTOFF 100
> > &END MGRID &QS
> > WF_INTERPOLATION PS
> > EXTRAPOLATION_ORDER 3
> > &END QS
> > &SCF
> > SCF_GUESS ATOMIC
> > ADDED_MOS 11
> > MAX_SCF 500
> > &END SCF
> > &XC
> > &XC_FUNCTIONAL PBE
> > &END XC_FUNCTIONAL
> > &END XC
> > &END DFT
> > &SUBSYS
> > &CELL
> > PERIODIC NONE
> > A 16 0 0
> > B 0 16 0
> > C 0 0 16
> > &END CELL
> > &COORD
> > C 0.0000015548 1.3995049822 0.0000112361
> > C 1.2105571712 0.6993498626 -0.0000011831
> > C 1.2105625355 -0.6993566874 -0.0000046545
> > C 0.0000152421 -1.3995045587 -0.0000022992
> > C -1.2105874557 -0.6993739468 0.0000097107
> > C -1.2105811121 0.6993813716 0.0000137609
> > F -0.0000016621 2.7455352497 -0.0000018655
> > F -2.3775341687 1.3700043040 0.0000017066
> > F -2.3775319035 -1.3700126878 -0.0000055826
> > F -0.0000018753 -2.7455346120 -0.0000011244
> > F 2.3775445180 -1.3700080734 0.0000004072
> > F 2.3775535520 1.3700123130 -0.0000037231
> > &END COORD
> > &KIND C
> > BASIS_SET DZVP-MOLOPT-SR-GTH
> > POTENTIAL GTH-PBE-q4
> > &END KIND
> > &KIND F
> > BASIS_SET DZVP-MOLOPT-SR-GTH
> > POTENTIAL GTH-PBE-q7
> > &END KIND
> > &END SUBSYS
> > &END FORCE_EVAL
> > &GLOBAL
> > PROJECT SINGLE-C6F6
> > RUN_TYPE SPECTRA
> > PRINT_LEVEL MEDIUM
> > &END GLOBAL
> > &MOTION
> > &GEO_OPT
> > OPTIMIZER CG
> > &CG
> > &LINE_SEARCH
> > TYPE 2PNT
> > &END LINE_SEARCH
> > &END CG
> > &END GEO_OPT
> > &END MOTION
>
> > As output for the excited states I obtained the following:
>
> > excited state : 1 5.205378
>
> > 33 -> 34 0.693 0.480
> > 32 -> 34 0.082 0.487
> > 20 -> 34 0.109 0.499
>
> > excited state : 2 7.547600
>
> > 33 -> 34 0.108 0.012
> > 32 -> 34 0.973 0.959
> > 21 -> 34 0.149 0.982
>
> > excited state : 3 7.785291
>
> > 33 -> 34 0.671 0.450
> > 32 -> 34 0.070 0.455
> > 31 -> 34 0.066 0.459
> > 20 -> 34 0.065 0.464
>
> > excited state : 4 8.544974
>
> > 31 -> 34 0.962 0.928
> > 19 -> 34 0.228 0.980
>
> > excited state : 5 8.663582
>
> > 30 -> 34 0.977 0.954
> > 13 -> 34 0.207 0.997
>
> > excited state : 6 9.602348
>
> > 29 -> 34 0.059 0.004
> > 28 -> 34 0.986 0.976
> > 18 -> 34 0.084 0.984
> > 11 -> 34 0.114 0.997
>
> > excited state : 7 9.771548
>
> > 29 -> 34 0.983 0.967
> > 28 -> 34 0.060 0.971
> > 17 -> 34 0.102 0.981
> > 10 -> 34 0.126 0.997
>
> > excited state : 8 10.868760
>
> > 27 -> 34 1.000 0.999
>
> > TDDFPT : CheckSum = 0.899094E+00
>
> > Now my question are:
>
> > Why there are only excitations to the first unoccupied orbital (34)
> > and no contributions higher orbitals (e.g. 35, 36 etc.) ?
>
> > Do I have to specify the number of unoccupied orbitals used in the
> > TDDFT section?
>
> > If, yes, where do have to specify this?
>
> > Sincerely,
> > Roman
>
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