The ABINIT Users Mailing List ( CLOSED )

[prendergast2@llnl.gov]

Can anyone give a clear explanation of ABINIT's approach to dealing with 
charged systems, (i.e. input variable: charge!=0) ? 

Basically, I need to know how nonneutral systems are treated in terms of the 
potentials used? Does the code just modify the periodic summations/integrals 
to include a uniform background charge density of equal but opposite 
magnitude to the value given by the variable 'charge', or is there more to 
it? For example is there screening between neighbouring unit cells to remove 
charge-charge interactions that would lead to finite size errors.

This question is relevant to the determination of quasiparticle gaps for 
finite systems using gamma point calculations (E_QP = E_N+1 + E_N-1 - 2 E_N).

Thanks for any insights.