1) maybe providing at least the inputs of the total, species1 and species2 runs
would help
2) is E_{species1} the energy of the whole cluster without the ligand?
3) what are the cell sizes and k-point grids used in the three calculations?
4) please kindly provide also your affiliation in posting to this forum, as
usually requested
Giovanni
> On 28 Nov 2016, at 12:03, Moosavi Seyed Mohamad
> <[email protected]> wrote:
>
> Hi
>
> I calculated the binding energy of a cluster (species1) with a ligand(species
> 2) with this formula:
> E_{total} - E_{species1} - E_{species2}
>
> I run PAW in a cubic cell large enough to avoid periodicity effects in the
> calculations (10 angstrom each side).
> The geometry converges very well to a 2.1 angstrom distance between species,
> as we expected.
>
> However, the results are surprising from two respects.
> First, the binding energy is too high. ~500 kcal/mol
>
> Second, when I add new monomer to species2 (make a dimer), in principle, the
> binding energy should remain constant (The bond length remains the same).
> However, I get extra ~200kcal/mol in the energy.
>
> The number of electrons:
> cluster (species1): 499
> monomer (species2): 60
> dimer (species2): 102
>
> So, something should be wrong with the formula or a scaling factor is needed
> here.
> I am wondering if you can guide me through this.
>
> Best regards
> Mohamad
>
>
>
>
> _______________________________________________
> Pw_forum mailing list
> [email protected] <mailto:[email protected]>
> http://pwscf.org/mailman/listinfo/pw_forum
> <http://pwscf.org/mailman/listinfo/pw_forum>
--
Giovanni Cantele, PhD
CNR-SPIN
c/o Dipartimento di Fisica
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
e-mail: [email protected]
Phone: +39 081 676910
Skype contact: giocan74
ResearcherID: http://www.researcherid.com/rid/A-1951-2009
Web page: http://people.na.infn.it/~cantele
_______________________________________________
Pw_forum mailing list
[email protected]
http://pwscf.org/mailman/listinfo/pw_forum
