sharc-md / sharc

The SHARC molecular dynamics (MD) program suite is an ab initio MD software package developed to study the excited-state dynamics of molecules.
https://www.sharc-md.org
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CPCMEQ and not predefined basis_per_element #93

Open jakobcasa opened 6 months ago

jakobcasa commented 6 months ago

Dear Sebastian

Both questions concern the traj production. Is it possible to let ORCA know to use the CPCMEQ keyword? Also, can we define a basis_per_element/basis_per_atom, which is not predefined in ORCA?

Thank you

Best Jakob

maisebastian commented 6 months ago

Dear Jakob, both questions might be solvable with the paste_input_file keyword for ORCA.template. This keyword takes a path as argument, to a file whose content is copied verbatim into the ORCA input. This option is an expert option, because if you put the wrong input blocks, you might break the SHARC-ORCA interface. But it should enable you to put any valid ORCA keywords.

According to https://sites.google.com/site/orcainputlibrary/basis-sets you can load external basis set files with "GTOname", so this might be what you are looking for.

For CPCM, note that I would not recommend that for trajectories, as C-PCM assumes that the solvent is always equilibrated to the solute. However, in reality, solvent equilibration takes on the order of at least tens of ps, so this assumption of instantaneous equilibration is not really varranted. If you are interested in realistic solvent dynamics, you should consider QM/MM.

Best, Sebastian

jakobcasa commented 6 months ago

Dear Sebastian

Thank you for the tip with the paste_input_file. I will look at it. For the CPCMEQ, we would start with the false option (e.g., not equilibrated), and then, after a specific time, which depends on the solvent's adaption to the solute's excited state, we would switch to true. (The change, we would introduce over a restart of the calculation).

Best Jakob

maisebastian commented 6 months ago

Dear Jakob, just to make you aware, even with CPCMQE=False, the calculation will equilibrate the solvent, but in this case it will be equilibrated to the electronic ground state. I.e., it does not mean that there is no equilibration involved.

Best, Sebastian