[CP2K:10520] Huge difference in adsorption energies between CP2K and VASP with PBE

Sharma SRK Chaitanya Yamijala sharma... at gmail.com
Fri Jul 13 23:59:03 UTC 2018


I just want to add that, the energy of the CO obtained through the one body
contributions (listed in the output of a BSSE calculation) and the energy
of the optimized CO (in the same cell size but without the slab) is found
to be exactly the same. To me, this suggests the current basis should be
accurate enough as one should expect a larger effect of the BSSE on CO
rather than on slab (as slab contributes to the large portion of basis
functions of the total system). Kindly, let me know if my logic is wrong.





--------------------------------------------------------------------
SRK *Chaitanya* Sharma, Yamijala.
http://www.bmwong-group.com/group-members/


On Fri, Jul 13, 2018 at 1:16 PM, Sharma SRK Chaitanya Yamijala <
sharma... at gmail.com> wrote:

> And I believe the increase in the adsorption energy could be because of
> the non-ground-state geometry of the "slab" during the BSSE calculation.
> The slab's absolute energy when considered in the monomer basis (for the
> ground state geometry) is -9804.47553 au and it is -9804.468056 au for the
> geometry in the dimer configuration (i.e. for the slab geometry in the
> "slab + CO" optimized geometry).
>
>
>
>
>
> --------------------------------------------------------------------
> SRK *Chaitanya* Sharma, Yamijala.
> http://www.bmwong-group.com/group-members/
>
>
> On Fri, Jul 13, 2018 at 12:29 PM, Sharma SRK Chaitanya Yamijala <
> sharma... at gmail.com> wrote:
>
>> Dear Prof. Hutter,
>>
>> I have performed the BSSE corrections and the results are given below.
>> Clearly, the BSSE corrected interaction energy is huge (~ 1 eV). If I
>> consider this CP-corrected energy as the adsorption energy (I have
>> calculated adsorption energy as Eads = EAB - EA -EB), then it will be too
>> off from the VASP (-0.466 eV) or FHIAIMs (-0.595 eV) results. As mentioned,
>> without BSSE the calculated adsorption energy is -0.863 eV. All the
>> energies given are with Grimme's-D3 dispersion. Kindly, let me know if you
>> have any comments about this.
>>
>> To check the accuracy of my basis set, I have started a run with TZVP
>> basis (instead of DZVP) for adsorption energy calculation and I will update
>> here.
>>
>> On a different note, the number of basis functions used for the
>> calculation in FHIAIMS (6172) and CP2K (5660) is roughly the same.
>>
>>  -----------------------------------------------------------
>> --------------------
>>  -
>> -
>>  -                                 BSSE RESULTS
>> -
>>  -
>> -
>>  -                 CP-corrected Total energy:
>> 0.039208                  -
>>  -
>> -
>>  -                       1-body contribution:
>> -9804.468056                  -
>>  -                       1-body contribution:
>> -21.667247                  -
>>  -
>> -
>>  -                       2-body contribution:
>> 9826.174511                  -
>>  -                 BSSE-free interaction energy:
>> 9826.174511               -
>>  -----------------------------------------------------------
>> --------------------
>>
>> Thanks,
>> Sharma.
>>
>>
>>
>>
>>
>> --------------------------------------------------------------------
>> SRK *Chaitanya* Sharma, Yamijala.
>> http://www.bmwong-group.com/group-members/
>>
>>
>> On Fri, Jul 13, 2018 at 12:31 AM, <hut... at chem.uzh.ch> wrote:
>>
>>> Hi
>>>
>>> you are using a DZVP basis, this is rather small. Check the number
>>> of basis functions. Do the same for the FHIaims calculation
>>> and compare.
>>> The cutoff of VASP cannot be compared to a local basis set.
>>>
>>> regards
>>>
>>> Juerg Hutter
>>> --------------------------------------------------------------
>>> Juerg Hutter                         Phone : ++41 44 635 4491
>>> Institut für Chemie C                FAX   : ++41 44 635 6838
>>> Universität Zürich                   E-mail: hut... at chem.uzh.ch
>>> Winterthurerstrasse 190
>>> CH-8057 Zürich, Switzerland
>>> ---------------------------------------------------------------
>>>
>>> -----cp... at googlegroups.com wrote: -----
>>> To: "cp2k" <cp... at googlegroups.com>
>>> From: "Sharma SRK Chaitanya Yamijala"
>>> Sent by: cp... at googlegroups.com
>>> Date: 07/12/2018 07:55PM
>>> Subject: Re: [CP2K:10514] Huge difference in adsorption energies between
>>> CP2K and VASP with PBE
>>>
>>> Dear Prof. Hutter,
>>>
>>> Thanks. I will try the BSSE correction with CP2K. Regarding k-point
>>> sampling, in both the softwares, I have used Gamma point only. Could you
>>> please elobarate your point on "size of basis sets" here? I don't know how
>>> should I compare VASP basis (plane waves) with CP2K (both PW and
>>> Gaussians)? I have converged the CUTOFFs in both the cases such that the
>>> energy differences are < 1 meV.
>>>
>>> Also, yesterday, I have performed similar calculations with FHIAims and
>>> I have obtained the adsorption energy (withOUT dispersion and BSSE
>>> corrections) as 0.412 eV which is again closer to the VASP result and to
>>> the result in the reference.
>>>
>>> Seeking your advice.
>>>
>>> Thanks,
>>> Sincerely,
>>> Sharma.
>>>
>>> On Thursday, July 12, 2018 at 12:11:59 AM UTC-7, jgh wrote:Hi
>>>
>>> my first guess: you didn't calculate the BSSE correction.
>>>
>>> other possible contributions: size of basis sets
>>>                               k-point sampling
>>>
>>> regards
>>>
>>> Juerg Hutter
>>> --------------------------------------------------------------
>>> Juerg Hutter                         Phone : ++41 44 635 4491
>>> Institut für Chemie C                FAX   : ++41 44 635 6838
>>> Universität Zürich                   E-mail: hut... at chem.uzh.ch
>>> Winterthurerstrasse 190
>>> CH-8057 Zürich, Switzerland
>>> ---------------------------------------------------------------
>>>
>>> -----cp... at googlegroups.com wrote: -----
>>> To: cp... at googlegroups.com
>>> From: "Sharma SRK Chaitanya Yamijala"
>>> Sent by: cp... at googlegroups.com
>>> Date: 07/12/2018 01:48AM
>>> Subject: [CP2K:10507] Huge difference in adsorption energies between
>>> CP2K and VASP with PBE
>>>
>>> Dear CP2K members,
>>>
>>> I am calculating the adsorption energies of CO on ZnO (4x4-slab with 4
>>> layers of ZnO(10-10) surface). The adsorption energy obtained from VASP is
>>> ~ 0.3 eV (without dispersion) and it is ~ 0.45 eV (with
>>> dispSECTION_PARAMETERS TRUEersion). However, when calculating the same
>>> system with CP2K (geometry is re-optimized), I am obtaining the energies
>>> 0.688 eV and 0.863 eV for without and with dispersion correction,
>>> respectively.
>>>
>>> The literature value is close to the VASP result. Here is the reference
>>> (kindly, see Table 2, C-down, 2x1 cell, Full).
>>>
>>> B Meyer and D Marx 2003 J. Phys.: Condens. Matter 15 L89
>>> http://iopscience.iop.org/article/10.1088/0953-8984/15/2/112/pdf
>>>
>>> Could anyone give an advice on why there is such a discrepancy in the
>>> adsorption energies irrespective of using the same functional?
>>>
>>> I am attaching the geometry and the input file for your reference.
>>>
>>> Thanks,
>>> Sharma.
>>>
>>> --------------------------------------------------------------------
>>> SRK Chaitanya Sharma, Yamijala.
>>> http://www.bmwong-group.com/group-members/
>>>
>>>
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>>> [attachment "1CO_on_opt_4x4_slab.xyz" removed by Jürg Hutter/at/UZH]
>>> [attachment "zno_bulk.inp" removed by Jürg Hutter/at/UZH]
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>>
>>
>
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