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saroc52

Member

Registered: 2025-04-12

Posts: 2

TDDFT_T1_excited state optimization

Hi Dr.Tian Lu and Sobereva

                             I have been dealing with TADF molecules. Facing an issue with TDDFT triplet state optimization, used optimized groud state geometry for both S1 and T1 TDDFT optimization by usinng orca. Method B3LYP/def2-svp with keyword

! B3LYP def2-SVP Grid6 NoFinalGrid VeryTightSCF OPT Nosym

%TDDFT
NROOTS    3
TDA    FALSE
IROOT    1
end

For triplet i used
! B3LYP def2-SVP Grid6 NoFinalGrid VeryTightSCF OPT Nosym

%TDDFT
NROOTS    3
TRIPLETS  TRUE
TDA    FALSE
IROOT    1
end

After the completion i ended up with almost simialr values and same coordinates..
-------------------------------
TD-DFT EXCITED STATES (SINGLETS)
--------------------------------

the weight of the individual excitations are printed if larger than 0.01

STATE  1:  E=   0.038274 au      1.041 eV     8400.1 cm**-1
   147a -> 148a  :     0.999200

STATE  2:  E=   0.059469 au      1.618 eV    13051.9 cm**-1
   147a -> 149a  :     0.990447

STATE  3:  E=   0.085224 au      2.319 eV    18704.5 cm**-1
   146a -> 148a  :     0.993491

TD-DFT EXCITED STATES (TRIPLETS)
--------------------------------

the weight of the individual excitations are printed if larger than 0.01

STATE  1:  E=   0.038137 au      1.038 eV     8370.0 cm**-1
   147a -> 148a  :     0.998536

STATE  2:  E=   0.059028 au      1.606 eV    12955.2 cm**-1
   147a -> 149a  :     0.984765

STATE  3:  E=   0.078299 au      2.131 eV    17184.6 cm**-1
   137a -> 151a  :     0.015822
   143a -> 148a  :     0.961806
and RMSD is 0 between S1 and T1 states...
kindly help me to solve the issue that what mistake i does....

Thankyou

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 2,011

Website

Re: TDDFT_T1_excited state optimization

To force ORCA to optimize T1 in the case 2, you should add "irootmult triplet", then the optimization will only consider the triplet excited states.

saroc52

Member

Registered: 2025-04-12

Posts: 2

Re: TDDFT_T1_excited state optimization

Thank you professor.