Hi,
I am trying to compute the excite state absorption S1->S2. I tried using Turbomole7.2 and Gaussian16. In Turbomole I only managed to get it to work using cc2 and I need to get the result with DFT. With gaussian I didn't get the absorption, just gradients.
Did anyone manage to do it? I have seen some reports that people have done the calculations but could not reproduce, probably because I don't know the correct input. I can also use other programs like qchem, dalton and orca if needed.
Thanks in advance,
Avishai
If you assume the S1->S2 occurs at minimum point of S1 potential energy surface, you should optimize S1 state. The TDDFT function of Gaussian is suitable for this purpose, for example, using "# PBE1PBE/6-311G* opt TD" keywords. In each optimization step, Gaussian prints excitation energy for each excited state. At the final optimization step, the difference of excitation energy of S2 and that of S1 is simply the excitation energy between S1->S2.
If you also need oscillator strength between S1 and S2 at TDDFT level, unfortunately Gaussian itself is unable to print it, but it can be easily obtained using Multiwfn (http://sobereva.com/multiwfn). Based on the optimized S1 geometry, you should perform a TDDFT task with keywords like "# PBE1PBE/6-311G* TD IOp(9/40=4)", then the resulting output file and fch file could be used to calculate oscillator strength between various excited states by Multiwfn (more information can be found in Section 3.21.5 of Multiwfn manual).
Below is an example of calculating transition electric dipole moments between excited states. After booting up Multiwfn, you should input following commands (corresponding files have already been provided in Multiwfn package):
examples\excit\4-nitroaniline.fch
18 // Electronic excitation analysis
5
examples\excit\4-nitroaniline.out
1 // Output transition dipole moments
Then you will see below information:
Transition dipole moment between excited states (a.u.):
i j X Y Z Diff.(eV) Oscil.str
1 1 0.3349295 -1.2198541 -0.0000000 0.00000 0.00000
1 2 -0.0000000 0.0000000 -0.0063711 0.22050 0.00000
1 3 0.0000000 -0.0000000 -1.5060977 0.52890 0.02939
2 2 0.2516659 -7.7974823 -0.0000000 0.00000 0.00000
2 3 0.0209292 0.0460680 -0.0000000 0.30840 0.00002
3 3 0.3340651 -1.4396632 -0.0000000 0.00000 0.00000
where i=1,j=2 term is the data corresponding to S1-S2 transition.
If you assume the S1->S2 occurs at minimum point of S1 potential energy surface, you should optimize S1 state. The TDDFT function of Gaussian is suitable for this purpose, for example, using "# PBE1PBE/6-311G* opt TD" keywords. In each optimization step, Gaussian prints excitation energy for each excited state. At the final optimization step, the difference of excitation energy of S2 and that of S1 is simply the excitation energy between S1->S2.
If you also need oscillator strength between S1 and S2 at TDDFT level, unfortunately Gaussian itself is unable to print it, but it can be easily obtained using Multiwfn (http://sobereva.com/multiwfn). Based on the optimized S1 geometry, you should perform a TDDFT task with keywords like "# PBE1PBE/6-311G* TD IOp(9/40=4)", then the resulting output file and fch file could be used to calculate oscillator strength between various excited states by Multiwfn (more information can be found in Section 3.21.5 of Multiwfn manual).
Below is an example of calculating transition electric dipole moments between excited states. After booting up Multiwfn, you should input following commands (corresponding files have already been provided in Multiwfn package):
examples\excit\4-nitroaniline.fch
18 // Electronic excitation analysis
5
examples\excit\4-nitroaniline.out
1 // Output transition dipole moments
Then you will see below information:
Transition dipole moment between excited states (a.u.):
i j X Y Z Diff.(eV) Oscil.str
1 1 0.3349295 -1.2198541 -0.0000000 0.00000 0.00000
1 2 -0.0000000 0.0000000 -0.0063711 0.22050 0.00000
1 3 0.0000000 -0.0000000 -1.5060977 0.52890 0.02939
2 2 0.2516659 -7.7974823 -0.0000000 0.00000 0.00000
2 3 0.0209292 0.0460680 -0.0000000 0.30840 0.00002
3 3 0.3340651 -1.4396632 -0.0000000 0.00000 0.00000
where i=1,j=2 term is the data corresponding to S1-S2 transition.
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