[Wien] GMAX

[Peer Kruse]

Let me see if I got it right:
if you do a DFT Calculation you try to find the eigenfunctions of not 
existing particles. These particles have the
nice characteristic to generate the same density and therefore the same 
potential distribution as real electrons.
For this you have to give a parameter , called GMAX, which gives you the 
accuracy of the potential and charge
you are interested in, as it describes the cut-off space-frequency of 
the devolopment of charge and potentials (the E_XC as well!).
So 1/gmax represents something like the lateral resolution of charge and 
potenial in direct space.
In this mailing list someone said that it is measured in the lovely unit 
 \sqrt{Ry}.

best regards

Peer

Claudio Lee wrote:

> Dear all,
>  
> Could anybody explain clearly the meaning of GMAX parameter in *in2 
> file. Physically, what does GMAX represent for?
>  
> Thank you in advance.
>  
> Best regards
>