Hi,
I want to know what keywords are used to know the strength value of excited states in the SF-TDDFT method.
For eg: when I do the single-point calculation using the TD-DFT method. In the output file, I am getting the strength value of each excited state.
Excited state 1: excitation energy (eV) = 2.2934
Total energy for state 1: -890.67525215 au
Multiplicity: Triplet
Trans. Mom.: 0.0000 X 0.0000 Y 0.0000 Z
Strength : 0.0000000000
D( 65) → V( 1) amplitude = 0.2583
D( 67) → V( 1) amplitude = 0.8981
D( 67) → V( 2) amplitude = -0.2258

Excited state 2: excitation energy (eV) = 3.4836
Total energy for state 2: -890.63151547 au
Multiplicity: Singlet
Trans. Mom.: 0.1612 X -2.8646 Y -0.4745 Z
Strength : 0.7217704923
D( 67) → V( 1) amplitude = 0.9670

But when I am doing SF-TDDFT calculations. I am not getting strength values in the output.
input:
$rem
BASIS = cc-pVDZ
EXCHANGE = omegaB97XD
OMEGA = 104
JOB_TYPE = sp
MAX_CIS_CYCLES = 100
SCF_CONVERGENCE = 8
MAX_SCF_CYCLES = 100
THRESH = 14
UNRESTRICTED = true
SPIN_FLIP = 1
CIS_N_ROOTS = 4
SYMMETRY_IGNORE = true
SYMMETRY = false
CIS_STATE_DERIVATIVE = 1
SOLVENT_METHOD = PCM
$end

output:Excited state 1: excitation energy (eV) = -2.1850
Total energy for state 1: -899.25802480 au
<S**2> : 0.0293
S( 2) → S( 1) amplitude = 0.9945 alpha

Excited state 2: excitation energy (eV) = 0.4820
Total energy for state 2: -899.16001222 au
<S**2> : 2.0048
S( 1) → S( 1) amplitude = 0.6614 alpha
S( 2) → S( 2) amplitude = 0.7411 alpha

Excited state 3: excitation energy (eV) = 1.1392
Total energy for state 3: -899.13585999 au
<S**2> : 0.0714
S( 1) → S( 1) amplitude = 0.7192 alpha
S( 2) → S( 2) amplitude = -0.6520 alpha

Excited state 4: excitation energy (eV) = 1.8313
Total energy for state 4: -899.11042750 au
<S**2> : 1.0375
D( 67) → S( 1) amplitude = -0.2834
S( 2) → V( 1) amplitude = 0.9448 alpha
Can anyone tell me which keywords help me to get strength values in the SF-TDDFT method?

Hi @jherbert
I want to ask one thing: I am using the SF-TDDFT method and used STS_MOM = True in $rem to check the oscillator strength value.
I got results like this:

The vertical excitation occurs from states 1 to 3 with a 1.365 strength value.
Then, I want to check the vertical de-excitation. I optimized the 3rd excited state by adding STS_MOM = True in $rem and checking the emission strength value. From the output, I got this:

can you please provide a complete input file? I do not understand what it means to say that you “optimized the 3rd excited state by adding STS_MOM = True”.

So those state-to-state (STS) transition moments should be between pairs of states at the geometry that you provided. There’s no distinction between excitation and de-excitation because what is output are matrix elements of the dipole moment operator between states |n> and |m>, and those are symmetric for real basis functions.

Thanks @jherbert
In the TD-DFT method, each excited state has a strength value. From there, we can say that S0 to S1 vertical excitation (absorption), wavelength (nm) has f (strength) = some value. Similarly, after excited state optimization, S1 to S0 vertical de-excitation (emission), wavelength (nm) has f (strength) = some value.

Can we also say this thing here in the SF-TDDFT method?