[Pw_forum] Problem with scf convergence

[Simon Binnie]

On Tue, 20 Mar 2012 16:15:09 +0100, Jonathan Trinastic  
<jptrinastic at phys.ufl.edu> wrote:

> Hi,
>
> I'm having an issue getting a Co-MgO interface to converge properly.
> Basically, the setup includes 8 layers of bcc Co  interfaced with 8
> layers of MgO, periodic in x and y and a vacuum between interfaces in
> the z direction.  I'm trying to find the Co-O distance that gives the
> energy minimum, so I'm trying to relax structures with varying distances
> - I'm using a 2.17 A distance to start based on experimental values.
> I've been able to relax the Co and MgO parts separately without a
> problem, but when I combine them they won't converge.
>

Have you tried experimenting with the mixing_mode parameter? I think I've  
bypassed similar problems with slabs in the past using the 'local-TF' mode.

Best regards,

Simon

-- 
Simon Binnie | Post Doc, Condensed Matter Sector
Scuola Internazionale di Studi Avanzati (SISSA)
Via Bonomea 256 | 34100 Trieste | sbinnie at sissa.it