[Pw_forum] DCC correction to electrostatic potential

[Nicholas E. Singh-Miller]

Dear Hai-Ping,

I am looking at espresso-4.1CVS.

Looking at the subroutines in EE/, it looks like the DCC correction is 
currently only coded for isolated systems -- in which case the 
calculataion of BCs for a CNT would cut through the charge density. (but I 
could be missing something).

Regads,

Nick

On Wed, 18 Feb 2009, lan haiping wrote:

> Dear All,
>
>  I did test calculations on DCC correction implemented in CVS version.
> I came to  problems when i examine the results of electrostatic potential.
> Would you please give me some hints ?
> My test calculation is a CNT (10,10)  system,  and the setting for
> DCC correction is
>        which_compensation ='dcc',
>        ecutcoarse = 100.0,
>        n_charge_compensation= 5,
>        nlev = 4,
>        whichbc(1)= 0, whichbc(2)=0,
>        whichbc(3)=1,
> But the final fermi energy i obtained is -3.99 eV, which is not consistent
> with
> previous report on workfunction of CNTs(about 4.6 eV ).
>
> Best,
> Hai-Ping
>
>
>

*****************************************
Nicholas E. Singh-Miller
Ph.D. Candidate
Prof. Marzari Group (quasiamore.mit.edu)
Materials Science and Engineering
Massachusetts Institute of Technology
13-4066
(617)324-0372
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