Excited state optimizations¶
It depends on the engine if it is possible to do an electronically excited state optimization, like an electronically excited state geometry optimization, transition state search, linear transit, PES scan, or IRC. Required is that the engine should be able to calculate the nuclear gradient for a particular electronically excited state. ADF and DFTB are engines that can do such calculation. If the excited state gradient is available one can also calculate an IR spectrum of the excited state, and one could calculate a vibrationally resolved electronic spectrum.
One should look in the documentation of the engine how to set up the calculation of the excited state gradient.