I am trying to calculate the UV-Vis spectra for a molecule using ORCA 4.1.3. I am using def2-TZVP basis set for the calculation, with the ground-state spin and charge being singlet and zero respectively. However, I am unable to understand few things, which are different from how such calculations are preformed in Gaussian.
1) In Gaussian, we have an option to calculate excitations to both Sn and Tn states, or to each of them separately. However, I am not yet clear if such an option exists in ORCA. I understand the existence of an option to calculate triplets, but then would it only calculate Tn states?
2) Assuming that ORCA natively calculates excitation to both Sn and Tn states, how can I understand which excitation corresponds to which state?
Dear Hemanth Haridas , I'm replying knowing well the version 4.2.1, I don't know whether this could apply for previous versions.
1) For Orca, the distinction of singlets vs triplets can be easily done. Let's consider using TD-DFT. If you ask:
%TDDFT NROOTS **
END
You will perform the calculation for ** singlet excited states. Nevertheless, if you want Orca to calculate also triplet excited states you can do:
%TDDFT NROOTS **
TRIPLETS TRUE
END
And Orca will calculate ** singlet excited states and ** triplet excited states.
2) Normally in the Output, you should find easily the following block ; for example in the image I join you (I'm sorry, I don't have an example with triplets... But Orca showed explicitely if it is triplet or singlet).
I hope this could help you !
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