Dears, since the periodicity of your ribbon is along z, your optical mesh should be denser accordingly (along z, as well). So I suppose the result with 1 x 1 x 64 is the correct one.
best Rocha On 29 July 2013 02:34, somayeh rudi <[email protected]> wrote: > Dear Mostafa > Thanks for your reply. My structure is an 5-armchair graphene nanoribbon > along the z direction. > i want to know that the optical mesh (1 1 64) that i used is correct or > not. i obtained different conductivities for optical mesh (1 1 64) and > optical mesh (64 1 1) , i m not sure which one gives the correct > conductivity. > -------------------------------------------- > On Sun, 7/28/13, Mostafa Shabani <[email protected]> wrote: > > Subject: Re: [SIESTA-L] optical mesh > To: [email protected] > Date: Sunday, July 28, 2013, 10:20 PM > > Dear somayeh. > I think Armchair Graphen Nano Ribone has 2D structure .you > have to pay attention for griding (kgrid_Monkhorst) > your > griding is for 1 0 0 0.5 1D structure > along Z Direction . Be > sure your structure is 1D or 2 D structure .And > 0 1 0 > 0.5 > 0 0 > 32 0.5xc.functional GGA , xc.authors > PBE Is better and exact approximation i think. > > > On Sun, Jul 28, 2013 at > 5:47 PM, somayeh rudi <[email protected]> > wrote: > > Dear > siesta users > > I m trying to calculate the optical properties of an > armchair GNR. > > can any one check my .fdf file and tell me if i defined my > parameters correctly.specially my optical mesh. > > > > I really appreciate any help. > > Best regards > > Somayeh Rudi > > > > here is my .fdf file: > > # AGNR N_a = 5 > > # > > > > SystemLabel AGNR > > NumberOfSpecies 2 > > NumberOfAtoms 14 > > > > %block ChemicalSpeciesLabel > > 1 6 C > > 2 1 H > > %endblock ChemicalSpeciesLabel > > > > %PAO.Basis <basis.fdf > > %PAO.BasisSize SZ > > %block PAO.BasisSizes > > C DZP > > H DZP > > %endblock PAO.BasisSizes > > > > > > %AtomicCoordinatesFormat ScaledCartesian # Format for > coordinates > > %AtomicCoorFormatOut Ang > > > > %block kgrid_Monkhorst_Pack > > 1 0 0 0.5 > > 0 1 0 0.5 > > 0 0 32 0.5 > > %endblock kgrid_Monkhorst_Pack > > > > MeshCutoff 210. Ry > > > > SolutionMethod diagon > > > > MaxSCFIterations 200 > > DM.MixingWeight 0.20 > > DM.Tolerance 1.d-5 > > DM.NumberPulay 4 > > ElectronicTemperature 300 K > > > > DM.UseSaveDM true > > UseSaveData true > > > > SpinPolarized false > > xc.functional LDA > > xc.authors CA > > > > WriteMullikenPop 1 > > SaveDeltaRho .true. > > SaveRho .true. > > SaveElectrostaticPotential .true. > > SaveTotalPotential .true. > > %block LocalDensityOfStates > > -3.0520 -2.8520 eV > > %endblock LocalDensityOfStates > > > > %block BandLines > > 1 0.000000 0.000000 0.0000 \Gamma > > 200 0.000000 0.000000 1.0000 X > > %endblock BandLines > > > > LatticeConstant 4.26258 Ang > > %block LatticeVectors > > 22.82899136 0.000 0.000 > > 0.000 16.00 0.000 > > 0.000 0.000 1.000 > > %endblock LatticeVectors > > > > AtomicCoordinatesFormat NotScaledCartesianAng > > %block AtomicCoordinatesAndAtomicSpecies > > 8.95349397 8. 1.42086 1 > > 8.95349397 8. 2.84172 1 > > 10.18399482 8. 3.55215 1 > > 10.18399482 8. 0.71043 1 > > 11.41449568 8. 1.42086 1 > > 11.41449568 8. 2.84172 1 > > 12.64499654 8. 3.55215 1 > > 12.64499654 8. 0.71043 1 > > 13.87549739 8. 1.42086 1 > > 13.87549739 8. 2.84172 1 > > 8. 8. 0.87036 2 > > 8. 8. 3.39222 2 > > 14.82899136 8. 0.87036 2 > > 14.82899136 8. 3.39222 2 > > %endblock AtomicCoordinatesAndAtomicSpecies > > > > # Calculation of dielectric function > > OpticalCalculation .true. > > Optical.Broaden 0.1 eV > > %block Optical.Mesh > > 1 1 64 > > %endblock Optical.Mesh > > #Optical.OffsetMesh .true. > > Optical.PolarizationType polarized > > %block Optical.Vector > > 0.000 0.000 1.000 > > %endblock Optical.Vector > > > > > > > > > > > > >
