first check systemlabel.EIG file, you will get fermi energy from that file. now draw clear line using set axis command of gnuplot at appropriate energy value from that you can distinguish band gap between CB &VB...
On Tue, Aug 4, 2015 at 10:47 AM, Altaf Ur Rahman <[email protected]> wrote: > Dear when you calculate the band structure by using like gnuplot you must > see the fermi energy from your band data file/EIG file and then when you > plot the you can write in the gnuplot this sentence > *set zero axis 3* > gnuplot> plot './Band.data' u ($1)+3.23:2 w l > > here in above case your fermi energy is 3.23 > and you can see the fermi line will appear that clearly distiguish the > conduction and valance band > > > > On Mon, Aug 3, 2015 at 6:04 PM, 毛飞 <[email protected]> wrote: > >> Dear siesta developers and users >> >> >> >> I am a newbie in band structure calculation. I calculate the band >> structure of LiF, and a 2*2*2 supercell of 64 atoms is selected. In this >> calculation, the local density approximation (LDA) is adopted for the >> exchange-correlation functional term, the band structure is obtained along >> the high symmetric line Γ->X->W->Γ, only gamma point is used for >> Brillouin zone sampling, more details can be found in the input file which >> is attached below. >> >> >> >> I can not understand the results of the E(k) (two figs are also >> attached), it seems there are two band gaps formed in the calculation (the >> Fermi energy is shifted to 0 eV), I want to know which one (gap 1 or gap >> 2) is the band gap in my calculation, and how does another gap come from? >> >> >> >> Is there anything wrong in the input file? >> >> >> >> Please help me, any suggestion or comment is appreciated. >> >> Sincerely >> >> >> >> Fei Mao >> >> University of South China, China >> >> >> >> ############################ Input file for the LiF >> ############################ >> >> SystemName bulk.LiF >> >> SystemLabel bulk_LiF >> >> >> >> NumberOfAtoms 8 >> >> NumberOfSpecies 2 >> >> >> >> %block ChemicalSpeciesLabel >> >> 1 3 Li >> >> 2 9 F >> >> %endblock ChemicalSpeciesLabel >> >> >> >> # basis >> >> PAO.BasisSize DZP >> >> PAO.EnergyShift 200 meV >> >> >> >> LatticeConstant 4.04 Ang # Lattice constant alat >> >> %block LatticeVectors # Lattice vectors, in units of >> latticeconstant >> >> 2.0 0.0 0.0 >> >> 0.0 2.0 0.0 >> >> 0.0 0.0 2.0 >> >> %endblock LatticeVectors >> >> >> >> >> >> %block SuperCell >> >> 2 0 0 0.0 >> >> 0 2 0 0.0 >> >> 0 0 2 0.0 >> >> %endblock SuperCell >> >> >> >> >> >> %block kgrid_Monkhorst_Pack >> >> 1 0 0 0.0 >> >> 0 1 0 0.0 >> >> 0 0 1 0.0 >> >> %endblock kgrid_Monkhorst_Pack >> >> >> >> >> >> BandLinesScale ReciprocalLatticeVectors >> >> %block BandLines >> >> 1 0.0 0.0 0.0 # Gamma-point >> >> 20 0.5 0.0 0.5 # X-point >> >> 30 0.5 0.25 0.75 # W-point >> >> 30 0.0 0.0 0.0 # Gamma-point >> >> %endblock BandLines >> >> >> >> >> >> %block ProjectedDensityOfStates >> >> -20 10 0.1 300 eV >> >> %endblock ProjectedDensityOfStates >> >> >> >> MeshCutoff 300.0 Ry >> >> >> >> # SCF options >> >> MaxSCFIterations 100 # Maximum number of SCF iter >> >> DM.NumberPulay 3 # One Pulay every 3 iter >> >> DM.MixingWeight 0.35 # New DM amount for next SCF cycle >> >> DM.Tolerance 5.d-4 # Tolerance in maximum difference >> >> >> >> SolutionMethod diagon # OrderN or Diagon >> >> OccupationFunction FD >> >> ElectronicTemperature 25 meV # Temp. for Fermi smearing >> >> >> >> # exchange-correlation functional >> >> XC.functional LDA >> >> XC.authors CA >> >> >> >> # structural infomation >> >> AtomCoorFormatOut Ang >> >> >> >> # output information >> >> WriteCoorXmol T >> >> WriteMDXmol T >> >> WriteForces T >> >> >> >> WriteKpoints .true. >> >> WriteEigenvalues .true. >> >> WriteKbands .true. >> >> WriteBands .true. >> >> WriteMullikenPop 1 >> >> >> >> # options for MD >> >> MD.MaxForceTol 0.01 eV/Ang >> >> MD.TypeOfRun CG >> >> MD.NumCGSteps 400 >> >> MD.Broyden.History.Steps 6 >> >> MD.Broyden.Initial.Inverse.Jacobian 1.0 >> >> >> >> # options for continue >> >> # MD.UseSaveCG T # neccessary! >> >> # MD.UseSaveXV T # neccessary! >> >> # DM.UseSaveDM true # to use continuae..ion files >> >> >> >> >> >> AtomicCoordinatesFormat Ang >> >> %block AtomicCoordinatesAndAtomicSpecies >> >> -5.963747 -2.022693 -2.026392 1 >> >> -6.051639 -5.949852 -2.013945 2 >> >> -2.147364 -2.056847 -2.009531 2 >> >> -2.039835 -5.953723 -2.024337 1 >> >> -6.085698 -1.925561 2.008577 2 >> >> -5.941415 -5.910826 2.052174 1 >> >> -2.040599 -2.032355 2.028040 1 >> >> -2.129653 -6.096888 2.008118 2 >> >> %endblock AtomicCoordinatesAndAtomicSpecies >> >> >> >> >> >
