add additional screening electrode layers, the length of the screening electrode layers. (not width, nor buffer)
2015-10-01 11:39 GMT+02:00 Seyed Mohammad Tabatabaei <[email protected]>: > Thank you very much. Do you mean I should add buffer layers or I must > only increase the width of my electrodes further? > > On 10/1/15, Nick Papior <[email protected]> wrote: > > You may have a longer ranging screening length of your electrode. > > > > Try and add more electrode layers. Generally you just want dQ to be as > low > > as possible, but sometimes it can be hard. > > > > See answer below: > > > > 2015-10-01 11:04 GMT+02:00 Seyed Mohammad Tabatabaei <[email protected]>: > > > >> Dear all, > >> > >> I have attached the three last steps of my transiesta convergence at 0 > >> Volts bias. Even at this bias, there exists a difference beween Qsol > >> and Qtot. > >> > >> Is this difference which is equal to 0.337 tolerable? > >> > >> Is there any method to assess the maximum tolerable difference in my > >> calculation? Does it cause my calculated currents to become invalid or > >> in any case the convergence is reached, the currents are valid? > >> > >> I have read many previous threads about this on the forum. In case my > >> questions are answered in some threads, I would be really grateful if > >> someone send the links. > >> > >> TranSiesta: Qsol,Qtot: 1008.337 1008.000 1.000 > >> transiesta: 20 -49567.1342 -49567.1262 -49567.1262 0.0003 > -3.0035 > >> TranSiesta: Qsol,Qtot: 1008.338 1008.000 1.000 > >> transiesta: 21 -49567.1436 -49567.1348 -49567.1348 0.0002 > -3.0035 > >> TranSiesta: Qsol,Qtot: 1008.339 1008.000 1.000 > >> transiesta: 22 -49567.1335 -49567.1341 -49567.1341 0.0001 > -3.0035 > >> TranSiesta: Qsol,Qtot: 1008.339 1008.000 1.000 > >> transiesta: 23 -49567.1320 -49567.1330 -49567.1330 0.0001 > -3.0035 > >> > >> One other critical question for me is that how should I know my Qtot > >> is correct? The parameters below are used in my calculation. The width > >> of my electrodes are about 11 Angstroms which guarantees nearest > >> neighbor only interactions. Is it correct that I increase the > >> TS.ComplexContour.NPoles, TS.ComplexContour.NCircle, > >> TS.ComplexContour.NLine, and TS.biasContour.NumPoints all by one and > >> see if Qtot is still equal to 1008.000? Is this what is called > >> convergence test? > >> > > Yes. > > And adding more electrode layers can/is also part of the convergence > test. > > > >> > >> Best wishes, > >> Mohammad, > >> > >> SystemName scat > >> SystemLabel scat > >> %block kgrid_Monkhorst_Pack > >> 6 0 0 0.0 > >> 0 1 0 0.0 > >> 0 0 3 0.0 > >> %endblock kgrid_Monkhorst_Pack > >> xc.functional GGA > >> xc.authors PBE > >> MeshCutoff 300.0 Ry > >> SolutionMethod transiesta > >> OccupationFunction MP > >> ElectronicTemperature 300 K > >> MaxSCFIterations 300 > >> DM.NumberPulay 6 > >> DM.NumberBroyden 0 > >> DM.MixingWeight 0.1000000000 > >> DM.OccupancyTolerance 0.1000000000E-11 > >> DM.NumberKick 0 > >> DM.KickMixingWeight 0.5000000000 > >> DM.Tolerance 0.1000000000E-03 > >> UseSaveData T > >> DM.UseSaveDM T > >> ON.UseSaveLWF T > >> MD.UseSaveXV T > >> MD.UseSaveCG T > >> MD.NumCGsteps 0 > >> MD.TypeOfRun CG > >> MD.VariableCell F > >> MD.MaxCGDispl 0.2000000000 Bohr > >> MD.MaxForceTol 0.02 eV/Ang > >> PAO.SplitNorm 0.15392 > >> PAO.BasisSize DZP > >> %include POSITIONS.fdf > >> # transiesta information > >> TS.MixH T > >> # GENGF OPTIONS > >> TS.ComplexContour.Emin -28 eV > >> TS.ComplexContour.NPoles 16 > >> TS.ComplexContour.NCircle 16 > >> TS.ComplexContour.NLine 10 > >> # BIAS OPTIONS > >> TS.biasContour.NumPoints 10 > >> TS.BiasContour.Eta 0.000001 Ry > >> # TS OPTIONS > >> TS.Voltage 0.0 eV > >> # TBT OPTIONS > >> TS.TBT.Emin -3 eV > >> TS.TBT.Emax +3 eV > >> TS.TBT.NPoints 500 > >> TS.TBT.NEigen 3 > >> TS.TBT.Eta 0.000001 Ry > >> # Write electrode hamiltonian > >> TS.SaveHS .true. > >> TS.SaveLead .true. > >> # LEFT ELECTRODE > >> TS.HSFileLeft ./elec.TSHS > >> TS.NumUsedAtomsLeft 48 > >> TS.BufferAtomsLeft 0 > >> # RIGHT ELECTRODE > >> TS.HSFileRight ./elec.TSHS > >> TS.NumUsedAtomsRight 48 > >> TS.BufferAtomsRight 0 > >> > > > > > > > > -- > > Kind regards Nick > > > -- Kind regards Nick
