[QE-users] O_ad(O-adsorption) is not binding at bridge position on Pt-surface
Ari P Seitsonen
Ari.P.Seitsonen at iki.fi
Tue Apr 10 11:58:27 CEST 2018
Dear Venkataramana Imandi,
Since you have fixed the lowest layers of the substrate, it sounds quasi
impossible that only few layers would have moved that much (the
interaction between the layers should be larger than the corrugation of
the potential energy surface of the oxygen). Of course the coverage is
quite high (1/2), but still I am surprised... Otherwise, I do not see
anything "obviously wrong" in your input now.
Greetings,
apsi
-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
Ecole Normale Supérieure (ENS), Département de Chimie, Paris
Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935
On Tue, 10 Apr 2018, Venkataramana Imandi wrote:
> Dear Ari,
>
> Sorry, I didn't mention that I also tried by fixing coordinate of O_ad at a bridge position.
> It resulted the Pt atoms moving, in such way that O_ad becomes three-fold site(either fcc or hcp).
>
> With best regards
> Venkataramana Imandi
> Postdoctoral fellow
> IIT Madras, India.
>
>
> On Tue, Apr 10, 2018 at 2:44 PM, Venkataramana Imandi <venkataramana.imandi at gmail.com> wrote:
>
> Dear QE community,
>
> I am a new user of Quantum espresso simulation package. I installed 6.2.1 Quantum espresso
> in the Linux-X86_64-INTEL-MPI. I want to find out the binding energy of O_ad at various
> sites(top,bridge,hcp and fcc) on Pt-surface and Pt-Ni alloy surface. In the beginning, i
> have tried on Pt-surface, and I got O_ad at top, hcp and fcc sites on Pt-surface, however,
> i couldn't find O_ad at bridge position.
> I have tried all possible ways of getting O_ad at the bridge position(between Pt-Pt). None
> of them were given succussful results, and the resulted O_ad comes to either fcc or hcp
> position. All possible ways: using with and without spin-polarization, davidson
> diagonalization anc cg, option (nosym = .TRUE. and .FALSE.), mixing mode(plain, local-TF
> and TF), changing mixing-beta(0.2, 0.3 and 0.5), neutral, negative charge(-2) and different
> simulation setup (present 24 atoms to 48 Pt atoms). The last option, i used different
> pseudopotential(Pt.pw91-n-van.UPF and O.pw91-van_ak.UPF), herein, i got error as follows
> (Error in scalartorealdp Too few elements found). Now i stopped trials.
> I ask you can anyone do calculation in your simulation setup with the given input file,
> tell me the where the problem is.
>
> I really thanks to you in advance for any suggestions regarding this.
> For information, i used VASP in the last year, therein, i obtained O_ad at all sites on
> Pt-surface.
>
> &control
> calculation='relax'
> restart_mode='from_scratch',
> pseudo_dir = '/home2/oth/ch18ipf01/pseudopotential2/',
> prefix='pt'
> tprnfor = .true.,
> nstep = 200
> /
> &system
> ibrav=0,
> nat=25,
> ntyp=2,
> ! nspin = 2,
> ! starting_magnetization(1)=0.7,
> ecutwfc = 32.0,
> ecutrho = 320.0,
> occupations='smearing',
> smearing='methfessel-paxton',
> degauss=0.02
> ! tot_charge = -2,
> nosym = .TRUE.
> /
> &electrons
> diagonalization='cg'
> conv_thr = 1.0e-6
> mixing_beta = 0.3
> electron_maxstep = 1000
> /
> &ions
> ion_dynamics='bfgs',
> /
> ATOMIC_SPECIES
> Pt 195.084 Pt.pbe-nd-rrkjus.UPF
> O 15.999 O.pbe-rrkjus.UPF
>
> ATOMIC_POSITIONS {angstrom}
> O 3.45091550 1.17466050 13.69732100 1 1 1
> Pt 4.84778787 1.20016667 12.44963917 1 1 1
> Pt 3.46185858 3.60066659 12.44963917 1 1 1
> Pt 2.07592929 1.20016667 12.44963917 1 1 1
> Pt 0.69000000 3.60066659 12.44963917 1 1 1
> Pt 3.46185858 0.40000000 10.18642611 1 1 1
> Pt 4.84778787 2.80049996 10.18642611 1 1 1
> Pt 0.69000000 0.40000000 10.18642611 1 1 1
> Pt 2.07592929 2.80049996 10.18642611 1 1 1
> Pt 3.46185858 2.00033330 7.92321305 1 1 1
> Pt 4.84778787 4.40083326 7.92321305 1 1 1
> Pt 0.69000000 2.00033330 7.92321305 1 1 1
> Pt 2.07592929 4.40083326 7.92321305 1 1 1
> Pt 4.84778787 1.20016667 5.66000000 1 1 1
> Pt 3.46185858 3.60066659 5.66000000 1 1 1
> Pt 2.07592929 1.20016667 5.66000000 1 1 1
> Pt 0.69000000 3.60066659 5.66000000 1 1 1
> Pt 3.46185858 0.40000000 3.39678694 0 0 0
> Pt 4.84778787 2.80049996 3.39678694 0 0 0
> Pt 0.69000000 0.40000000 3.39678694 0 0 0
> Pt 2.07592929 2.80049996 3.39678694 0 0 0
> Pt 3.46185858 2.00033330 1.13357388 0 0 0
> Pt 4.84778787 4.40083326 1.13357388 0 0 0
> Pt 0.69000000 2.00033330 1.13357388 0 0 0
> Pt 2.07592929 4.40083326 1.13357388 0 0 0
>
> K_POINTS {automatic}
> 3 3 1 0 0 0
> CELL_PARAMETERS {angstrom}
> 5.5437171600 0.0000000000 0.0000000000
> 0.0000000000 4.8009999000 0.0000000000
> 0.0000000000 0.0000000000 25.5792783300
>
>
> With best regards
> Venkataramana Imandi
> Postdoctoral fellow
> IIT Madras, India.
>
>
?? ?
>
>
>
>
>
>
> --
> venkataramana
>
>
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