[Pw_forum] London Dispersion force: DFT-D2
Elliot S. MENKAH
elliotsmenkah at yahoo.com
Tue May 3 20:26:02 CEST 2016
Thank you all for the invaluable help.
I would implement what has been shared and repost should I need further
help.
Thank you.
Kind Regards,
Elliot
On 05/03/2016 09:24 AM, Marzari Nicola wrote:
>
>> . Can anyone enlighten me on the status of vdw functionals for spin
>> polarised calculations?
>>
>
>
> This prl http://arxiv.org/abs/1509.03759 - nicola
>
>
>> Cheers,
>> ————————————————————————
>> Martin P. Andersson
>> Associate Professor
>> Nano-Science Center, Department of Chemistry
>> University of Copenhagen, Denmark
>>
>> Tel: +45 3532 0280
>> Mobile: +46 733 893091
>> E-mail: ma at nano.ku.dk <mailto:ma at nano.ku.dk>
>> ————————————————————————
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>> On 03 May 2016, at 10:26, Giuseppe Mattioli
>>> <giuseppe.mattioli at ism.cnr.it <mailto:giuseppe.mattioli at ism.cnr.it>>
>>> wrote:
>>>
>>>
>>> Dear Elliot
>>> I do not know if I understand well your questions, but I try to answer:
>>>
>>>> Could someone please assist me as to how to account for London
>>>> dispersion forces with QE or essentially how to do a DFT-D2 calculation
>>>> with the the aim of accounting for the energy contribution of
>>>> dispersion
>>>> forces.
>>>
>>> Use vdw_corr='grimme-d2'
>>> You will find in the output the dispersion force contribution to the
>>> total energy:
>>>
>>> ! total energy = -2369.89004091 Ry
>>> Harris-Foulkes estimate = -2369.89004090 Ry
>>> estimated scf accuracy < 0.00000001 Ry
>>>
>>> The total energy is the sum of the following terms:
>>>
>>> one-electron contribution = -22567.16723495 Ry
>>> hartree contribution = 11423.49753189 Ry
>>> xc contribution = -757.02966668 Ry
>>> ewald contribution = 9530.66102736 Ry
>>> Dispersion Correction = -0.98373910 Ry
>>> Hubbard energy = 1.13399751 Ry
>>> smearing contrib. (-TS) = -0.00195694 Ry
>>>
>>>> I'm trying to account for the energy contribution of London dispersion
>>>> forces on the total energy of a hydrazine-nickel system.
>>>
>>> Remember that DFT-D2 badly overestimate the interaction of molecules
>>> with metal surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg,
>>> H. A
>>> consistent and accurate ab initio parametrization of density
>>> functional dispersion correction (DFT-D) for the 94 elements H-Pu.
>>> J. Chem. Phys. 2010,
>>> 132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or
>>> vdwdf-c09 (see usage and related papers in QE documentation).
>>>
>>>> ------------------------------
>>>> &CONTROL
>>>> tefield = .TRUE.,
>>>> dipfield = .TRUE.,
>>>> disk_io = 'low',
>>>>
>>>> &SYSTEM
>>>> edir=3,
>>>> emaxpos=0.65,
>>>> eopreg=0.06,
>>>> eamp=0,
>>>> ------------------------------
>>>>
>>>
>>> This is a well tested but old and complex machine to correct the
>>> interaction of a dipole with its periodic replicas along z. I do not
>>> know if it is
>>> possible to estimate its impact on dispersion forces in a different
>>> way than by using/not using the dipole correction and check the
>>> difference between
>>> the above "Dispersion Correction" contribution to the total energy.
>>> However, I've satisfactorily used for a system similar to yours
>>> (thiol SAM on Au
>>> surface) this new setup (again, read the documentation and related
>>> papers), which decouple in a simpler way the dipole along z.
>>>
>>> &system
>>> input_dft='vdw-df-c09'
>>> assume_isolated = 'esm',
>>> esm_bc='bc1',
>>> /
>>>
>>> HTH
>>> Giuseppe
>>>
>>>
>>> On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
>>>> Hi all,
>>>> I'm trying to account for the energy contribution of London dispersion
>>>> forces on the total energy of a hydrazine-nickel system.
>>>>
>>>> Could someone please assist me as to how to account for London
>>>> dispersion forces with QE or essentially how to do a DFT-D2 calculation
>>>> with the the aim of accounting for the energy contribution of
>>>> dispersion
>>>> forces.
>>>>
>>>> When I correct the net-surface dipole on a system by using the
>>>> variables
>>>> and values below, does it affect the energy from dispersion forces, if
>>>> so, how?
>>>> How does correcting the net-surface dipole relate to accounting for
>>>> dispersion forces?
>>>>
>>>> ------------------------------
>>>> &CONTROL
>>>> tefield = .TRUE.,
>>>> dipfield = .TRUE.,
>>>> disk_io = 'low',
>>>>
>>>> &SYSTEM
>>>> edir=3,
>>>> emaxpos=0.65,
>>>> eopreg=0.06,
>>>> eamp=0,
>>>> ------------------------------
>>>>
>>>>
>>>> I'm basically trying to account for London dispersion forces on a
>>>> hydrazine-nickel system.
>>>> Any info to help my computation would be gladly appreciated.
>>>> Thank you
>>>>
>>>> Kind Regards,
>>>> Elliot
>>>
>>> ********************************************************
>>> - Article premier - Les hommes naissent et demeurent
>>> libres et égaux en droits. Les distinctions sociales
>>> ne peuvent être fondées que sur l'utilité commune
>>> - Article 2 - Le but de toute association politique
>>> est la conservation des droits naturels et
>>> imprescriptibles de l'homme. Ces droits sont la liberté,
>>> la propriété, la sûreté et la résistance à l'oppression.
>>> ********************************************************
>>>
>>> Giuseppe Mattioli
>>> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
>>> v. Salaria Km 29,300 - C.P. 10
>>> I 00015 - Monterotondo Stazione (RM), Italy
>>> Tel + 39 06 90672836 - Fax +39 06 90672316
>>> E-mail: <giuseppe.mattioli at ism.cnr.it
>>> <mailto:giuseppe.mattioli at ism.cnr.it>>
>>> http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
>>> ResearcherID: F-6308-2012
>>>
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--
Elliot Sarpong Menkah
Graduate Student - Computational Chemistry / Computational Material Science.
Theoretical and Computational Chemistry
Dept. of Chemistry
Kwame Nkrumah University of Science and Technology (KNUST),
Private Mail Bag,
Kumasi,
Ghana.
Mobile:+233-243-055-717,+233-202-929-058
Alt. Email: esmenkah at knust.edu.gh
elliotsmenkah at gmail.com
elliotsmenkah at hotmail.com
webpage: http://chemistry.knust.edu.gh/MMC/group-members/ESMenkah
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