dear siesta
hi
i want receive optical calculation of cnt(3,3) by siesta 2.0.2, i do this work 
but don't know which value of broaden is suitable because i receive f-sum rule 
error, in my band structure energy rang is: -23 to 19 , should i put this value 
for optical max.energy: (E.max - E.min + 2*broaden ) i.e 42 + 2*broaden ? my 
fdf is:
SystemLabel      cnt

NumberOfAtoms    12
NumberOfSpecies  1

%block ChemicalSpeciesLabel
    1    6  C
%endblock ChemicalSpeciesLabel

PAO.Basis <basis.fdf

%block kgrid_Monkhorst_Pack
 1  0   0    0.0
 0  1   0    0.0
 0  0  20    0.5
%endblock kgrid_Monkhorst_Pack

MeshCutoff           280 Ry

LatticeConstant 2.457726 Ang

%block LatticeVectors
 10.000   0.000  0.0000
 0.0000   10.00  0.0000
 0.0000   0.000  1.0000
%endblock LatticeVectors

AtomicCoordinatesFormat NotScaledCartesianAng
%block AtomicCoordinatesAndAtomicSpecies
 2.064591     0.000000    -1.232141     1
 1.575573     1.334205    -1.232141     1
 1.032295     1.787988     0.000000     1
-0.367669     2.031589     0.000000     1
-1.032295     1.787988    -1.232141     1
-1.943242     0.697384    -1.232141     1
-2.064591     0.000000     0.000000     1
-1.575573    -1.334205     0.000000     1
-1.032295    -1.787988    -1.232141     1
 0.367669    -2.031589    -1.232141     1
 1.032295    -1.787988     0.000000     1
 1.943242    -0.697384     0.000000     1


%endblock AtomicCoordinatesAndAtomicSpecies

SpinPolarized         .false.
xc.functional         GGA
xc.authors            PBE

SolutionMethod        diagon

MaxSCFIterations      200
DM.MixingWeight       0.20
DM.Tolerance          1.d-5
DM.NumberPulay         4
ElectronicTemperature  300 K

DM.UseSaveDM          .true.
UseSaveData          .true.

WriteMullikenPop       1
WriteBands        .true.
BandLinesScale       ReciprocalLatticeVectors
%block BandLines
1   0.0      0.0      0.0  \Gamma
30  0.0      0.0      0.5  X
%endblock BandLines
WriteForces             T
PAO.Basis size  DZP

MD.MaxForceTol          0.001 eV/Ang
MD.UseStructFile        F

SaveRho                       .true.  
SaveDeltaRho                  .true.
SaveElectrostaticPotential    .true.
SaveTotalPotential            .true.

WriteCoorXmol       T
OpticalCalculation       .true.
Optical.EnergyMinimum     0 eV
Optical.EnergyMaximum     100 eV
Optical.Broaden           0.02 eV
Optical.Scissor           0 eV
Optical.Number of Bands  All bands
%block Optical.Mesh
  1 1 60
%endblock Optical.Mesh
Optical.OffsetMesh        .true.
Optical.Polarization Type   Polarized
%block Optical.Vector
0.0 0.0 1.0
%endblock Optical.Vector 

Responder a