Dear Martin There is a brand-new implementation of vdwdf by Thonhauser and his group (Thonhauser, T.; Zuluaga, S.; Arter, C. A.; Berland, K.; Schröder, E.; Hyldgaard, P. Spin Signature of Nonlocal Correlation Binding in Metal-Organic Frameworks. Phys. Rev. Lett. 2015, 115, 136402) which handles well open- shell systems. It has been added to v 5.2.1 or v 5.3.0. Time ago I did some "handmade correction" to DFT-D2 to investigate the absorption of zinc phthalocianine on ZnO by using some force-field derived (AMBER or CHARMM, I do not remember well) C6 coefficients. I ended in using vdwdf, though... HTH Giuseppe
On Tuesday, May 03, 2016 10:56:54 AM Martin Andersson wrote: > Hi Elliot, > > Indeed, standard DFT-D2 does overestimate adsorption on metals, but a > modified DFT-D2 version that I published doesnât ;) > > http://www.hindawi.com/journals/jtc/2013/327839/ > <http://www.hindawi.com/journals/jtc/2013/327839/> > > I havenât tried adsorption onto Ni surfaces specifically, but bulk Ni > properties came out fine and adsorption on quite a few other metals (including > Pt, Au, etc) gives quite reasonable results. In fact, it would be quite > interesting for me to see if adsorption on Ni behaves as well as other > surfaces, so by all means, try it out. > > I donât use the vdw functionals in my research and have only read up on > their progress briefly, but as far as I understood, they were not able to > handle spin polarised systems initially, like Ni. Can anyone enlighten me on > the status of vdw functionals for spin polarised calculations? > > Cheers, > ââââââââââââââââââââââââ > 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] > ââââââââââââââââââââââââ > > > On 03 May 2016, at 10:26, Giuseppe Mattioli <[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/ > > <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 > > <http://pwscf.org/mailman/listinfo/pw_forum> ******************************************************** - 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]> http://www.ism.cnr.it/en/staff/giuseppe-mattioli/ ResearcherID: F-6308-2012 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
