# CCL:G: Electron Transfer Integral Calculation

*From*: Adam Kubas <ad.kubas(~)gmail.com>
*Subject*: CCL:G: Electron Transfer Integral Calculation
*Date*: Mon, 17 Sep 2018 07:58:16 +0200

Dear Kalyan,
it depends on the method you want to use for H_ab calculations. If you want
to stick to GMH approach then any wave-function method that gives access to
exciation energy, excited state dipole moment and transition dipole moment
can be used, many of them are implemented in Gaussian. Free ORCA software
has number of useful methods, inlcuding efficient multireference
approaches. Try to avoid TD-DFT, except some tricks you can play for
symmetric dimers it will not provide good H_ab estimates.
Constrined DFT and very efficient POD methods is nicely implemented in free
CP2K. Simple fragment charge difference method is available online using
eCoupling server (http://ecouplingserver.bsc.es/) - it can use otput of
multiple programs including Gaussian. Examples are provided.
In NWChem you can use corresponding orbital transformation (only UHF
orbitals are supported), just look for 'Electron transfer' in the manual.
Some FO approach should also be there if I remember correctly. They have
CDFT module as well but no coupling calculations (although you can feed
such charge-localized orbitals to ET module providing you set density
functional to 100% HFX).
(a bit of self-advertising comes here, sorry)
In case you are interested you can have a look at our benchmarks of various
approaches to calculate H_ab:
1) J. Chem. Phys. 140, 104105 (2014)
2) PCCP 17, 14342 (2015)
Best wishes,
Adam
2018-09-16 22:16 GMT+02:00 Kalyan Jyoti Kalita kkalyanjyoti||gmail.com <
owner-chemistry{:}ccl.net>:
>
> Sent to CCL by: "Kalyan Jyoti Kalita" [kkalyanjyoti/a\gmail.com]
> Dear all,
>
> I am interested in calculation electron charge transfer integral from a
> series of dimers of a molecule. But our research group don't have ADF
> software. Does anyone know how to calculate charge transfer integral using
> Gaussian16 software or any other freeware which can be used to calculate
> transfer integral?
>
> Thank you in advance.
>
> Kalyan Jyoti Kalita
> Indian Institute of Science Education and Research (IISER) Kolkata>
>
>