ABINIT Discussion Forums

Hi Everyone,

I am calculating the linear and non-linear optics. I use the input variables as :
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0.01 ! Value of the *smearing factor*, in Hartree
0.010 1 ! frequency *step* and *maximum* frequency (Ha)
0.000 ! *Scissor* shift if needed, in Hartree
0.001 ! *Tolerance* on closeness of singularities (in Hartree)
3 ! *Number of components* of linear optic tensor to be computed
11 33 23 ! Linear *coefficients* to be computed (x=1, y=2, z=3)
2 ! Number of components of nonlinear optic tensor to be computed
123 222 ! Non-linear coefficients to be computed
.........................................................................................
I draw the linear and non-linear optics, but they aren't good and haven't agreement with other works.
Could anybody help me to find the reason. I have used the toptic_1.in as :
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ndtset 6
#First dataset : SC run with kpoints in the IBZ
iscf1 3
nband1 24
nstep1 250
kptopt1 1
nbdbuf1 0
prtden1 1 getden1 0 getwfk1 0 ! Usual file handling data

#Second dataset : NSC run with large number of bands, and points in the IBZ
iscf2 -2
nband2 200 ! This number of bands might be too low for non-linear optics and real part of linear optics
nstep2 250
kptopt2 1
getwfk2 1 getden2 1 ! Usual file handling data

#Third dataset : NSC run with large number of bands, and points in the the full BZ
iscf3 -2
nband3 200 ! This number of bands might be too low for non-linear optics and real part of linear optics
nstep3 250
kptopt3 3
getwfk3 2 getden3 1 ! Usual file handling data
#Fourth dataset : ddk response function along axis 1
iscf4 -3
nband4 200 ! This number of bands might be too low for non-linear optics and real part of linear optics
nstep4 1 nline4 0
kptopt4 3
nqpt4 1 qpt4 0.0d0 0.0d0 0.0d0
rfdir4 1 0 0
rfelfd4 2
getwfk4 3
#Fifth dataset : ddk response function along axis 2
iscf5 -3
nband5 200 ! This number of bands might be too low for non-linear optics and real part of linear optics
nstep5 1 nline5 0
kptopt5 3
nqpt5 1 qpt5 0.0d0 0.0d0 0.0d0
rfdir5 0 1 0
rfelfd5 2
getwfk5 3
#Sixth dataset : ddk response function along axis 3
iscf6 -3
nband6 200 ! This number of bands might be too low for non-linear optics and real part of linear optics
nstep6 1 nline6 0
kptopt6 3
nqpt6 1 qpt6 0.0d0 0.0d0 0.0d0
rfdir6 0 0 1
rfelfd6 2
getwfk6 3
#Data common to all datasets
nshiftk 1
shiftk 0.5 0.5 0.5
ngkpt 4 4 4 ! This is much too low : should be at least 24x24x24
acell 10.938662993 10.938662993 10.938662993
angdeg 3*56.654541304
ntypat 2
znucl 49 8
natom 10
spgroup 167 # There are two atoms
spgaxor 2
typat 1 1 1 1 2 2 2 2 2 2 # They both are of type 1, that is, Silicon.
xred # Reduced coordinate of atoms
0.35770000 0.35770000 0.35770000
0.64230000 0.64230000 0.64230000
...
...
...

#Definition of the planewave basis set
ecut 21 # Maximal kinetic energy cut-off, in Hartree



amu 114.820000 15.9994000
diemac 10.0

iscf 3
ixc 3
nbdbuf 2

tnons 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
0.0000000 0.0000000 0.0000000 0.5000000 0.5000000 0.5000000
0.5000000 0.5000000 0.5000000 0.5000000 0.5000000 0.5000000
-0.0000000 -0.0000000 -0.0000000 -0.0000000 -0.0000000 -0.0000000
-0.0000000 -0.0000000 -0.0000000 0.5000000 0.5000000 0.5000000
0.5000000 0.5000000 0.5000000 0.5000000 0.5000000 0.5000000
tolwfr 1.e-20
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Thank you.
Asadi.