I`m trying include core corrections on rare earth, but I can`t find in the manual how can I do. Some one could help-me.
Cheers,
Luiz Adolfo
Em 12/03/2010 12:00, Marcos Veríssimo Alves < [email protected] > escreveu:
Peter,
Have you tried including BSSE corrections? Check the list email
archive, and the literature, for further info on BSSE corrections.
Cheers,
Marcos
On Fri, Mar 12, 2010 at 3:42 PM, Süle Péter wrote:
>
>
> Dear SIESTA users,
>
> I'm trying to determine the cohesive energy
> of different compounds and I'am faced with the problem
> of overbinding using SIESTA.
> Just for an example case I tested simple bcc Fe.
> I get Ecohes < -10 eV/atom using standard DZP
> basis and various pseudos available in the atm dir
> (with and without semi core 3d74s1, pseudo core, normal
> 3d64s2 config). The acceptable value would be Ec > -5. eV/atom.
> I have no idea how to improve the results.
> It could be that further expansion of the basis set to TZP or sg.
> could help a bit, although in published papers I found that
> DZP is already good for Fe.
> The calculation of Ec is as follows: Ec=E(a0)-2*E_atom
> or Ec=E(a0)-E(inf), where E(inf) is sg. like a=30. Ang.
> It could be I should play with the parameters
> PAO.EnergyShift 50 meV
> PAO.SplitNorm 0.15
>
> MeshCutoff 200.0 Ry
>
> Best regards, Peter Sule
>
>
>
> ----------------------------------------------------
> Dr. Peter Sule
> senior research associate
> Institue for Technical Physics and Materials Science
> (MTA-MFA), Konkoly-Thege M. 29-33, Budapest, Hungary
> tel.: (36) 1 392 2222/3605
> fax.: (36) 1 392 22 73
> www.mfa.kfki.hu/~sul e / [email protected]
> -----------------------------------------------------
>
>
>
> My typical fdf file looks like:
>
> SystemName bcc fe
> SystemLabel fe
>
> NumberOfAtoms 2
> NumberOfSpecies 1
>
> %block ChemicalSpeciesLabel
> 1 26 Fe
> %endblock ChemicalSpeciesLabel
>
> #PAO.BasisType nodes
> PAO.BasisSize DZP
> #PAO.EnergyShift 50 meV
> #PAO.SplitNorm 0.15
>
> #MeshCutoff 200.0 Ry
>
> #SpinPolarized T
>
> MaxSCFIterations 550
> DM.MixingWeight 0.01
> DM.NumberPulay 4
> DM.Tolerance 1.d-4
> #DM.UseSaveDM
>
> SolutionMethod diagon #orderN
>
> ElectronicTempe rature 3500 K
>
> Diag.ParallelOverK
>
> XC.functional GGA
> XC.authors PBE
>
> AtomicCoordinatesFormat Fractional
>
> %block AtomicCoordinatesAndAtomicSpecies
> ck AtomicCoordinatesAndAtomicSpecies
> 0.0 0.0 0.0 1 # Fe 1
> 0.5 0.5 0.5 1 # Fe 2
> %endblock AtomicCoordinatesAndAtomicSpecies
>
> LatticeConstant 2.87
>
>
