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adc-connect / adcc

adcc: Seamlessly connect your program to ADC
https://adc-connect.org
GNU General Public License v3.0
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ESP charges #82

Open Edumars opened 4 years ago

Edumars commented 4 years ago

Hello developers, is there any way of computing ESP charges associated with a given excited ADC state? In other words, is there any implementation of the calculation of atomic charges (preferably electrostatic fitted charges, but otherwise a population analysis could be a reasonable substitute), using the state ADC(2) density matrix? If there is any difference, I would prefer an implementation within pyscf, rather than psi4. Thanks a lot

maxscheurer commented 4 years ago

Hi,

currently there is no such option to obtain ESP charges or similar population analysis. These would need to be computed backend-side (i.e., making use of pyscf or psi4 directly) because detailed information about the AO basis, evaluation of electrostatic potentials on a grid, etc., are required; all of which have nothing to do with an ADC calculation itself.

Thus, it's easier to implement this feature in user code because a lot of programming and design effort would be required to interface the necessary routines in a unified way to adcc.

So, this could be a good starting point in order to write your own ESP/RESP code. The only problem is that you would need to evaluate the ESP (dot product of the integrals with the density matrix) yourself, since the given code computes the ESP inside psi4, i.e., there's no way to pass the ADC density matrix. However, all required functionality (integrals etc.) is in principle available in either pyscf or psi4.