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
