Dear Hande, thanks for your detailed information and sorry for the late reply. Actually I found out the mistake. When I performed optimization of the slab surface alone I kept fix some atoms position.
By the way, I thought to implement van der Waals corrections (!vdw_corr ='grimme-d3'). Can I use such correction with any pseudopotentials? Thanks again Paolo 2018-07-26 10:30 GMT-04:00 Hande Toffoli <[email protected]>: > Dear Paolo, > > Assuming everything was set up correctly (for which I would have to see > your input files), the magnitude of the adsorption energy is way too large > to be accounted for by dipole corrections. What I would suggest is for you > to isolate the TiO2 slab from Anastase_Surface_without_H_anisole_1.out > and run an scf calculation on it. I would then see what the difference is > with the final energy you obtain from Anastase_Surface_without_H.out. If > the difference is very large, there's your answer. This suggestion is > triggered by the observation that the reconstruction on the "bottom" > surface of the slabs in the two output files appears different. This may > not be the answer but worth a shot. > > Beyond this, there are a couple things to note about your calculations. > The first one is that it appears that you are not using van der Waals > corrections. Since your molecules are perpendicular, it shouldn't matter > that much but most commonly, such a molecule would adsorb in the parallel > configuration, so presumably you will investigate that configuration as > well. So it may be worthwhile investigating the effect of some vdW schemes. > Secondly, your molecule appears to travel a lot on the slab during the > geometry optimization. This is a little unusual, I would investigate this. > > Hope this helps. > Hande > > On Wed, Jul 25, 2018 at 7:01 PM, Paolo Costa <[email protected]> > wrote: > >> >> Dear experts, >> >> I got nonsense value of adsorption energy by computing 4-iodoanisole on >> top of TiO2 anastase surface (101). >> By calculating : (Esurface+anisole)-Eanisole-Esurface, I got an >> adsoprtion energy of 0.66 ry (8.98 eV), which is too high. >> Now I am trying to apply the dipole correction to see if this is the >> problem causing an unusual adsorption energy. >> In attachment I put the output files. >> I would be glad to receive any suggestions to understand the problem. >> >> Thanks. >> >> Paolo >> -- >> Paolo Costa, Ph.D. >> Postdoctoral Researcher >> Department of Chemistry and Biomolecular Sciences >> University of Ottawa >> 10 Marie Curie, Ottawa, ON K1N 6N5, Canada >> Room number: DRO 326 (D'Iorio Hall) >> >> _______________________________________________ >> users mailing list >> [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users >> > > > > -- > Hande Toffoli > Department of Physics > Office 439 > Middle East Technical University > Ankara 06800, Turkey > Tel : +90 312 210 3264 > https://www.compmatsci.com/ > > > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users > -- Paolo Costa, Ph.D. Postdoctoral Researcher Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie, Ottawa, ON K1N 6N5, Canada Room number: DRO 326 (D'Iorio Hall)
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