[QE-users] O_ad(O-adsorption) is not binding at bridge position on Pt-surface

Venkataramana Imandi venkataramana.imandi at gmail.com
Tue Apr 10 13:10:34 CEST 2018


Dear Ari,

I misunderstood your message.
I ask you whether you got stable O_ad position at a bridge site.

With best regards
Venkataramana Imandi
Postdoctoral fellow
IIT Madras, India.


On Tue, Apr 10, 2018 at 3:50 PM, Venkataramana Imandi <
venkataramana.imandi at gmail.com> wrote:

> Dear Ari,
>
> What shall i do now. The wrong in the input file coordinates or system
> description.
> Can you give more hints. Even increasing system size (present 24 atoms to
> 48 Pt atoms), the results remain same.
>
> With best regards
> Venkataramana Imandi
> Postdoctoral fellow
> IIT Madras, India.
>
>
> On Tue, Apr 10, 2018 at 3:08 PM, Venkataramana Imandi <
> venkataramana.imandi at gmail.com> 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
>>
>
>
>
> --
> venkataramana
>



-- 
venkataramana
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