sorry, it is 'change the kpoint until the energy/atom (eV) change is less than 0.01eV ?'
-- Best Regards 邱芳瑜 Chiu Fang Yu 國立成功大學 材料科學與工程學系碩二 MOBILE：0930287221(中華) GMAIL：[email protected] <[email protected]> 2014-12-17 14:55 GMT+08:00 joyce79928cc . <[email protected]>: > > I was wondering how to decide whether it is converge? > change the kpoint until the energy(eV) change is less than 0.01eV or...? > Thanks! > > -- > Best Regards > > 邱芳瑜 Chiu Fang Yu > 國立成功大學 材料科學與工程學系碩二 > MOBILE：0930287221(中華) > GMAIL：[email protected] <[email protected]> > > > > 2014-12-17 14:51 GMT+08:00 joyce79928cc . <[email protected]>: >> >> Thanks for reply. I will try to fix it! >> >> -- >> Best Regards >> >> 邱芳瑜 Chiu Fang Yu >> 國立成功大學 材料科學與工程學系碩二 >> MOBILE：0930287221(中華) >> GMAIL：[email protected] <[email protected]> >> >> >> >> 2014-12-17 14:38 GMT+08:00 <[email protected]>: >>> >>> Dear joyce79928: >>> >>> just some ideas. >>> Your results may be noise due to insufficient basis and/or >>> insufficient k-mesh ans/or insufficient MeshCutoff >>> (probably all three). >>> Does your DOS have any resemblance with what is expected for a 1-dim. >>> chain? >>> Does your stress definition in the GeometryConstrains block >>> serve any purpose? >>> There is a number of works with Siesta on Au chains around, >>> maybe scroll through them first. >>> Anyway, you can systematically proceed in the following way: >>> >>> Take just one atom along the chain step, not three >>> (make the third lattice vector shorter :-). >>> Fix it. >>> For the k-mesh, you need just 1 point in the plane but more than 4 >>> along Z. >>> Run a sequence of calculations just varying the 3d lattice vector >>> (chain step) - single point, no relaxation. >>> Trace the total energy curve as function of chain step. >>> This will give you an approximation to "true Siesta" result. >>> Study how it depends on basis, k-mesh and MeshCutoff. >>> Find "good" values for all three. >>> Make the usual "egg box" test. >>> Then hopefully your forces will be OK so that >>> you can add more atoms to your unit, release them, let them relax etc. >>> >>> Good luck >>> >>> Andrei >>> >>> [email protected] >>> >>> >>> > Dear: >>> > >>> > I want to relax the chain with Siesta. >>> > but different atom position with same parameter will get different >>> > structure. >>> > for example, I set the distance between chain to 2.93 A and get a final >>> > structure of 2.569 A between chain. >>> > Then I change initial chain distance to 2.88 A and get a final >>> structure >>> > of >>> > 2.758 A between chain. >>> > >>> > why this happened? >>> > >>> > Thanks for reading my mail and it is welcome to discuss with me. >>> > >>> > below's are my fdf input file. >>> > >>> > SystemName bulk_au >>> > SystemLabel bulk_au >>> > >>> > ================================================== >>> > ================================================== >>> > # SPECIES AND BASIS >>> > >>> > # Number of species >>> > NumberOfSpecies 1 >>> > %block ChemicalSpeciesLabel >>> > 1 79 Au >>> > %endblock ChemicalSpeciesLabel >>> > >>> > PAO.BasisSize SZP >>> > PAO.EnergyShift 0.04 Ry >>> > >>> > >>> > # K-points >>> > >>> > %block kgrid_Monkhorst_Pack >>> > 4 0 0 0.0 >>> > 0 4 0 0.0 >>> > 0 0 4 0.5 >>> > %endblock kgrid_Monkhorst_Pack >>> > >>> > >>> > # UNIT CELL AND ATOMIC POSITIONS >>> > >>> > # UNIT CELL >>> > LatticeConstant 1.0 Ang >>> > %block LatticeVectors >>> > 8.81553253 0.00000000 0.00000000 >>> > 4.40776625 7.63447409 0.00000000 >>> > 0.00000000 0.00000000 8.79434817 >>> > %endblock LatticeVectors >>> > >>> > # Atomic coordinates >>> > NumberOfAtoms 3 >>> > AtomicCoordinatesFormat ScaledCartesian >>> > %block AtomicCoordinatesAndAtomicSpecies >>> > 4.407766232 4.241374236 0.00000000 1 >>> > 4.407766232 4.241374236 2.93144939 1 >>> > 4.407766232 4.241374236 5.86289878 1 >>> > %endblock AtomicCoordinatesAndAtomicSpecies >>> > >>> > ================================================== >>> > ================================================== >>> > # General variables >>> > >>> > ElectronicTemperature 300 K >>> > MeshCutoff 200. Ry >>> > xc.functional LDA # Exchange-correlation functional >>> > xc.authors CA >>> > SpinPolarized .false. >>> > SolutionMethod Diagon >>> > >>> > >>> > # SCF variables >>> > >>> > DM.MixSCF1 T >>> > MaxSCFIterations 300 # Maximum number of SCF iter >>> > DM.MixingWeight 0.03 # New DM amount for next SCF cycle >>> > DM.Tolerance 1.d-4 # Tolerance in maximum difference >>> > DM.UseSaveDM true # to use continuation files >>> > DM.NumberPulay 5 >>> > #Diag.ParallelOverK yes >>> > >>> > # MD variables >>> > >>> > MD.FinalTimeStep 1 >>> > MD.TypeOfRun CG >>> > MD.NumCGsteps 50 >>> > MD.VariableCell T >>> > UseSaveData T >>> > >>> > # Output variables >>> > >>> > WriteMullikenPop 1 >>> > WriteBands .false. >>> > SaveRho .false. >>> > SaveDeltaRho .false. >>> > SaveHS .false. >>> > SaveElectrostaticPotential True >>> > SaveTotalPotential no >>> > WriteCoorXmol .true. >>> > WriteMDXmol .true. >>> > WriteMDhistory .false. >>> > WriteEigenvalues yes >>> > >>> > %block GeometryConstraints >>> > stress 4 5 6 >>> > position 1 >>> > %endblock GeometryConstraints >>> > >>> > >>> > >>> > -- >>> > Best Regards >>> > >>> > 邱芳瑜 Chiu Fang Yu >>> > 國立成功大學 材料科學與工程學系碩二 >>> > MOBILE：0930287221(中華) >>> > GMAIL：[email protected] <[email protected]> >>> > >>> >>> >>> >>> >>>
