Dear all,

Can someone provide me an example of input for optimization of excited state using EOM-CC method? how should I assign the root to be optimized?

Thank you very much.

Michael Morgan

Dear all,

Can someone provide me an example of input for optimization of excited state using EOM-CC method? how should I assign the root to be optimized?

Thank you very much.

Michael Morgan

This may help, with `optimize`

instead of `gradient`

. The roots spec is there and here’s a bit more. Unless you know a better example, @amjames?

Thank you very much.

I think ROOTS_PER_IRREP is to assign the number of excited states to calculate, not the state to optimize. Am I wrong? In other program such as Gaussian or GAMESS, for EOM-CC calculation, it need always assign the number of states to calculate and the state to optimize (root and nstate).

@MMichael If no other problems arise I believe that the optimization will search for the minimum on the PES for the highest root requested.

I believe there is no way to select a particular root to optimize, but I may be mistaken there. I do know that we can’t select a single root to compute an energy, for example if you wanted the energy of the 3rd A1 root for water you would need to compute all 3 and not just the one you are interested in.

I hate to pass the buck again, but @Rollin_King may be able to provide more help.

PROP_ROOT should let you select the state you wish to optimize (or compute properties for). By default, PROP_ROOT is the highest state you converged. (Occasionally, it is helpful for convergence purposes to optimize an additional state.) In complicated cases, one can also specify PROP_SYM if you are converging states for multiple irreps, then you will want to specify.

Thanks for all of you. Problem solved.