[ase-users] ASE made Pt(111) surface, cannot converge in VASP

[Protik Das]

It seems like a vasp issue rather than ASE issue. Your POSCAR should be
alright. Some comments regarding vasp:

1. You used 3.98 angstrom for the bulk lattice constant. Are you sure that
is the optimized lattice constant for the theory level (LDA/GGA) you are
using? If this is not, it might effect convergence. I would suggest doing a
full relaxation of bulk Pt and then using that lattice constant to create
surface.

2. When you used 15 angstrom as vacuum value, it basically adding 15
angstrom vacuum in each direction. That means you are adding 30 angstrom
vacuum which may be little too large.

3. As Pt is a metal, you need to pay close attention to ISMEAR and SIGMA
values. Take a look here:
http://cms.mpi.univie.ac.at/vasp/guide/node124.html .



On Mon, Jun 19, 2017 at 6:39 AM Zhang, Qiang <zhang.5671 at buckeyemail.osu.edu>
wrote:

> Hello Protik Das,
>
>
> I just try to relax this created surface POSCAR. It is not converging.
> Thanks for your time.
>
>
> Sincerely,
>
>
> Qiang Zhang
> ------------------------------
> *From:* Protik Das <protik77 at gmail.com>
> *Sent:* Monday, June 19, 2017 2:09:52 AM
>
> *To:* Zhang, Qiang; ase-users at listserv.fysik.dtu.dk
> *Subject:* Re: [ase-users] ASE made Pt(111) surface, cannot converge in
> VASP
> What calculation are you doing? Did you relax your surface before these
> calculations?
>
> On Sun, Jun 18, 2017 at 10:54 PM Zhang, Qiang via ase-users <
> ase-users at listserv.fysik.dtu.dk> wrote:
>
>> Dear ASE users,
>>
>>
>> I use ase to to make a Pt(111) surface
>>
>> from ase.build import fcc111
>> from ase.io import write
>> slab = fcc111('Pt', size=(3,3,4), a=3.98, vacuum=15.0)
>> #write('pt111.xyz', slab)
>>
>> slab.write('POSCAR', vasp5=True)
>>
>> I use the POSCAR (fix the bottom two Pt layers) for VASP calculation, but it is take long time without converging. Is there something wrong with my script? Thanks for your time.
>>
>>
>> Sincerely,
>>
>> Qiang Zhang
>>
>> _______________________________________________
>> ase-users mailing list
>> ase-users at listserv.fysik.dtu.dk
>> https://listserv.fysik.dtu.dk/mailman/listinfo/ase-users
>
> --
> Protik Das,
> ECE Graduate Student,
> LATTE (http://latte.ece.ucr.edu),
> University of California, Riverside.
>
-- 
Protik Das,
ECE Graduate Student,
LATTE (http://latte.ece.ucr.edu),
University of California, Riverside.
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