The ABINIT Users Mailing List ( CLOSED )

[Ronaldo Giro <rgiro@macbeth.if.usp.br>]

Dear Zhenhua Zeng

The Abinit can calculate the average eletrostatic potential by using 
the keyword prt1dm. This corresponds to averaging the potential or the density
on bi-dimensional slices of the FFT grid. To do it you need to perform 
just 1SCF calcultion on your structure. 

Once you 
have the average potencial (it is microscopic planar average) you need 
to calculate the macroscopic average in order to obtain the 
Fermi energy of material with respect to the macroscopic 
average potential. Ps: I am not sure about this, because 
this procedure is adopted to calculate the Schottky barrier height (SBH). 
I think that to obtain the work function is similar. 

For more details about this procedure (SBH) see the paper: 
-R. G. Dandrea and C. B. Duke - J. Vac. Sci. Technol. A 11(4), 
848-853 (1993).
-C. Berthod et al. - J. Vac. Sci. Technol. B 14(4), 3000-3007 (1996).






Quoting Zhenhua Zeng <myid520@163.com>:

> Dear abinit users,
> 
>     It can be seen that someone had similar problem with me. I want to
> calculate the work function of transition metal Au and adsorbate-substrate
> system of oxygen atom adsorbing on Au(111) surface. 
> 
>     I known the work function is calculated as the difference between the
> average electrostatic potential in the vacuum and the Fermi energy of the
> slab(same as the formula gived by paul). Abinit can give the Fermi energy in
> output file. But I want to known how to get the average electrostatic
> potential in the vacuum. 
> 
>     VASP can give average electrostatic potential at each ion from V4.4.4 by
> using parameter and utility. I want to known if abinit has the similar
> function. Does there have someone who have experience of calculating work
> function. Your help will be greatly appreciated!
> 
> Best regards.
> Zhenhua Zeng
> Hunan University, PR. china
> 
> 
> 
> 
> 
> >From: pnuber@yahoo.com 
> >To: forum@abinit.org 
> >Subject: Calculation of molecular work function 
> >Date: Thu, 15 Jul 2004 11:53:30 +0200 
> >
> >Dear All
> >
> >I wish to use abinit to calculate the work function of carbon 
> >nanotubes. Does it make sense to do it by:
> >Phi = phi - mu
> >(Phi=work function, phi=electrostatic potential at vacuum of supercell 
> >and
> >mu = fermi energy)?
> >
> >Does anybody have experience on doing this? How well is the agreement 
> >with experiment?
> >
> >regards
> >paul 
> 
>