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: [email protected] <mailto:[email protected]> >> ———————————————————————— >> >> >> >> >> >> >> >> >> >> >>> On 03 May 2016, at 10:26, Giuseppe Mattioli >>> <[email protected] <mailto:[email protected]>> >>> 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: <[email protected] >>> <mailto:[email protected]>> >>> http://www.ism.cnr.it/en/staff/giuseppe-mattioli/ >>> ResearcherID: F-6308-2012 >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> [email protected] <mailto:[email protected]> >>> http://pwscf.org/mailman/listinfo/pw_forum >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] <mailto:[email protected]> >> http://pwscf.org/mailman/listinfo/pw_forum -- 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: [email protected] [email protected] [email protected] webpage: http://chemistry.knust.edu.gh/MMC/group-members/ESMenkah
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