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Re: Calculating energies of FC and relaxed first excited state

dummy@example.com (sobereva) — Sun, 14 Jan 2024 06:17:24 +0000

Yes

Re: Calculating energies of FC and relaxed first excited state

dummy@example.com (sonalis) — Sat, 13 Jan 2024 13:18:25 +0000

That means I do not need to carry out two # TD opt calculations and I have to look for the first and last total energies, E (TD-HF/TD-DFT) printed in the same output file. Thank you so much, Sir.

Re: Calculating energies of FC and relaxed first excited state

dummy@example.com (sobereva) — Fri, 12 Jan 2024 19:30:09 +0000

Because this topic is irrelevant to wavefunction analysis, I moved it to quantum chemistry board.

The steps you need (For Gaussian users):
1 Optimize ground state
2 Based on optimized geometry of ground state, perform task with # TD opt [method/basis set]. By default, the first excited state is optimized. The 1st excited state energy printed first time corresponds to energy of FC point, while that printed finally corresponds to energy at the relaxed geometry.

Calculating energies of FC and relaxed first excited state

dummy@example.com (sonalis) — Fri, 12 Jan 2024 10:42:40 +0000

Hello Sir. I wish to calculate the energy of FC as well as relaxed first excited state of a molecule in gas phase.
So, using the optimized ground state geometry, I need to do opt td(root=1) calculation to get the energy and geometry of FC state. Then for relaxed first excited state energy and geometry, I have to take the output coordinates of FC geometry as the input file and again run opt td(root=1) calculation. Is that correct, Sir?