Not necessarily. State 3A can be any triplet electronic state, even the ground state. T1 is usually the lowest-energy triplet excited state.

If you want to optimize T1 via TDDFT, then you need the keywords:

# TD=(triplets,nstates=M,root=1) opt

# other keywords you require

By the way, for me it is not clear what is taking a long time, the optimization of 3A via UDFT?

Best, Pablo

Thank you for the clarification.

Regarding the question: I was trying to optimize the 3A state of a molecule using the DFT method but it was not converging. Should I use the UDFT method?

Best regards

Gourav

Dear Gourav Das , yes using UDFT should relax the orbitals and the triplet state should converge.

Best, Pablo