ABINIT Discussion Forums

what is the recommended method to calculate ionisation energies for molecules?

as the simple minded person i am, i intended to just calculate total energies for the neutral and for the 1x ionised system, but how do i actually set up the latter? can i set an additional electron on the configuration? if yes, how?

thanks for any comments and suggestions.

R.

Hello,


Look at the input variable called "charge", it allows you to remove or add electrons from the system (charge 2 means your system is in charge +2, with two electrons removed). You have to be carefull about that due to periodic replicas of the charge (see for example Makov, G. & Payne, M. C. Periodic boundary conditions in ab initio calculations Phys. Rev. B, American Physical Society, 1995, 51, 4014)


Another way of calculating ionisation energies would be through GW computations (more complicated though but then you wont need the charged system for your purpose). See the related tutorials http://www.abinit.org/documentation/helpfiles/for-v7.0/tutorial/lesson_gw1.html


Hope it helps,

David

thanks for the response. i'll try it out.