No ARPACK/ngARPACK library in conda-forge installation about dftbplus HOT 4 OPEN

Dear @danieleveclani,

at the moment the MPI-enabled binary of DFTB+ (e.g. 'dftbplus==mpi_mpich_' and 'dftbplus==mpi_openmpi_') does not support excited state calculations within the Casida formalism, regardless whether installed via conda-forge or compiled from source. I'm afraid you have to stick with the serial binary (e.g. 'dftbplus==nompi_') for now, however that might change very soon as we are already working on MPI-parallelizing this part of the code, see PR #1274.
Unfortunately your calculation will not run with the serial version either, since third order DFTB3 is not supported in combination with the excited state functionality yet. If you have any additional questions don't hesitate to reach out to us, I hope my response is somewhat helpful to you.

Best regards
Tammo

from dftbplus.

Dear Tammo,

Thank you for your clear reply. Waiting for your further implementations.

Best,
Daniele.

from dftbplus.