dear elk users and elk developers
please tell me?
Is it possible to run the bootstrap procedure (TDDFT) with no scissor shift (scissor=0)?
please as soon as possible.
thanks a lot
Last edit: amirhossein 2014-09-14
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Dear elk developers
I want to calculate the dielectric function of an organic crystal within the framework of TDDFT using the bootstrap approximation. The RPA calculations have been done succesfully, and the kohn-sham band gap was 2.7eV. but when the bootstrap procedure is performed with no scissor shift the error "tddft calculations faild to converge" appears, and when the scissor shif is set to be non zero value,(for example 0.1), the tddft calculations can finish with no error. but the imaginary tddft-epsilons has nonzero values at the static limit and the strange peaks appears at nagative energies. it is spected that the imaginary epsilon (for semiconductors) be zero at the static limit and if crystal has some kindes of excitonic peaks thay should appear at the positive energies not at negative energies.
here is my elk.in file:
tasks
0
120
121
320
lmaxvr
3
lradstp
2
gmaxrf
0.0
fxctype
210
gmaxrf
0.0
fxctype
210
gmaxvr
14
nempty
2
maxscl
10
rgkmax
2.5
scissor
0.0
dosmsum
.true.
swidth
0.005
xctype
20 0 0
! components of the optical tensor
optcomp
1 1
2 2
3 3
Dr. Sharma will know better, but I believe you need a nonzero G vector for the response function. gmaxrf=1.5 or so. This will greatly increase computational expense (memory I believe mostly) but I believe if you have gmaxrf=0 you are still going to get the RPA results as LFE are not included.
Best
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
With bootstrap kernel (fxctype=210), even with gmaxrf=0 the results include excitonic effects and should be different from RPA results (if material has excitons).
Increasing gmaxrf will include local field efects. In most cases these effects are quite small.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
dear elk users and elk developers
please tell me?
Is it possible to run the bootstrap procedure (TDDFT) with no scissor shift (scissor=0)?
please as soon as possible.
thanks a lot
Last edit: amirhossein 2014-09-14
Dear elk developers
I want to calculate the dielectric function of an organic crystal within the framework of TDDFT using the bootstrap approximation. The RPA calculations have been done succesfully, and the kohn-sham band gap was 2.7eV. but when the bootstrap procedure is performed with no scissor shift the error "tddft calculations faild to converge" appears, and when the scissor shif is set to be non zero value,(for example 0.1), the tddft calculations can finish with no error. but the imaginary tddft-epsilons has nonzero values at the static limit and the strange peaks appears at nagative energies. it is spected that the imaginary epsilon (for semiconductors) be zero at the static limit and if crystal has some kindes of excitonic peaks thay should appear at the positive energies not at negative energies.
here is my elk.in file:
tasks
0
120
121
320
lmaxvr
3
lradstp
2
gmaxrf
0.0
fxctype
210
gmaxrf
0.0
fxctype
210
gmaxvr
14
nempty
2
maxscl
10
rgkmax
2.5
scissor
0.0
dosmsum
.true.
swidth
0.005
xctype
20 0 0
! components of the optical tensor
optcomp
1 1
2 2
3 3
wplot
500 100 0 : nwplot, ngrkf, nswplot
-0.44 2 : wplot
mixtype
2
avec
27.53876227 0.000000000 0.000000000
0.000000000 10.50992833 0.000000000
0.000000000 0.000000000 21.11045522
sppath
'/.../'
atoms
3 : nspecies
'H.in' : spfname
44 : natoms; atposl, bfcmt below
0.34100000 0.52900000 0.10100000 0.00000000 0.00000000 0.00000000
0.65900000 0.47100000 0.60100000 0.00000000 0.00000000 0.00000000
0.15900000 0.02900000 0.60100000 0.00000000 0.00000000 0.00000000
0.84100000 0.97100000 0.10100000 0.00000000 0.00000000 0.00000000
0.34700000 0.34800000 0.99500000 0.00000000 0.00000000 0.00000000
0.65300000 0.65200000 0.49500000 0.00000000 0.00000000 0.00000000
0.15300000 0.84800000 0.49500000 0.00000000 0.00000000 0.00000000
0.84700000 0.15200000 0.99500000 0.00000000 0.00000000 0.00000000
0.46430000 0.05890000 0.97680000 0.00000000 0.00000000 0.00000000
0.53570000 0.94110000 0.47680000 0.00000000 0.00000000 0.00000000
0.03570000 0.55890000 0.47680000 0.00000000 0.00000000 0.00000000
0.96430000 0.44110000 0.97680000 0.00000000 0.00000000 0.00000000
0.45250000 0.51590000 0.24940000 0.00000000 0.00000000 0.00000000
0.54750000 0.48410000 0.74940000 0.00000000 0.00000000 0.00000000
0.04750000 0.01590000 0.74940000 0.00000000 0.00000000 0.00000000
0.95250000 0.98410000 0.24940000 0.00000000 0.00000000 0.00000000
0.57450000 0.33910000 0.33790000 0.00000000 0.00000000 0.00000000
0.42550000 0.66090000 0.83790000 0.00000000 0.00000000 0.00000000
0.92550000 0.83910000 0.83790000 0.00000000 0.00000000 0.00000000
0.07450000 0.16090000 0.33790000 0.00000000 0.00000000 0.00000000
0.71990000 0.08080000 0.40000000 0.00000000 0.00000000 0.00000000
0.28010000 0.91920000 0.90000000 0.00000000 0.00000000 0.00000000
0.78010000 0.58080000 0.90000000 0.00000000 0.00000000 0.00000000
0.21990000 0.41920000 0.40000000 0.00000000 0.00000000 0.00000000
0.83330000 0.80950000 0.42160000 0.00000000 0.00000000 0.00000000
0.16670000 0.19050000 0.92160000 0.00000000 0.00000000 0.00000000
0.66670000 0.30950000 0.92160000 0.00000000 0.00000000 0.00000000
0.33330000 0.69050000 0.42160000 0.00000000 0.00000000 0.00000000
0.84930000 0.50890000 0.28620000 0.00000000 0.00000000 0.00000000
0.15070000 0.49110000 0.78620000 0.00000000 0.00000000 0.00000000
0.65070000 0.00890000 0.78620000 0.00000000 0.00000000 0.00000000
0.34930000 0.99110000 0.28620000 0.00000000 0.00000000 0.00000000
0.75440000 0.48830000 0.12100000 0.00000000 0.00000000 0.00000000
0.24560000 0.51170000 0.62100000 0.00000000 0.00000000 0.00000000
0.74560000 0.98830000 0.62100000 0.00000000 0.00000000 0.00000000
0.25440000 0.01170000 0.12100000 0.00000000 0.00000000 0.00000000
0.64080000 0.82640000 0.98730000 0.00000000 0.00000000 0.00000000
0.35920000 0.17360000 0.48730000 0.00000000 0.00000000 0.00000000
0.85920000 0.32640000 0.48730000 0.00000000 0.00000000 0.00000000
0.14080000 0.67360000 0.98730000 0.00000000 0.00000000 0.00000000
0.57340000 0.66020000 0.05740000 0.00000000 0.00000000 0.00000000
0.42660000 0.33980000 0.55740000 0.00000000 0.00000000 0.00000000
0.92660000 0.16020000 0.55740000 0.00000000 0.00000000 0.00000000
0.07340000 0.83980000 0.05740000 0.00000000 0.00000000 0.00000000
'C.in' : spfname
52 : natoms; atposl, bfcmt below
0.48630000 0.11560000 0.04910000 0.00000000 0.00000000 0.00000000
0.51370000 0.88440000 0.54910000 0.00000000 0.00000000 0.00000000
0.01370000 0.61560000 0.54910000 0.00000000 0.00000000 0.00000000
0.98630000 0.38440000 0.04910000 0.00000000 0.00000000 0.00000000
0.44602000 0.30860000 0.10260000 0.00000000 0.00000000 0.00000000
0.55398000 0.69140000 0.60260000 0.00000000 0.00000000 0.00000000
0.05398000 0.80860000 0.60260000 0.00000000 0.00000000 0.00000000
0.94602000 0.19140000 0.10260000 0.00000000 0.00000000 0.00000000
0.47990000 0.38820000 0.21210000 0.00000000 0.00000000 0.00000000
0.52010000 0.61180000 0.71210000 0.00000000 0.00000000 0.00000000
0.02010000 0.88820000 0.71210000 0.00000000 0.00000000 0.00000000
0.97990000 0.11180000 0.21210000 0.00000000 0.00000000 0.00000000
0.55252000 0.28230000 0.26550000 0.00000000 0.00000000 0.00000000
0.44748000 0.71770000 0.76550000 0.00000000 0.00000000 0.00000000
0.94748000 0.78230000 0.76550000 0.00000000 0.00000000 0.00000000
0.05252000 0.21770000 0.26550000 0.00000000 0.00000000 0.00000000
0.72689000 0.96150000 0.34380000 0.00000000 0.00000000 0.00000000
0.27311000 0.03850000 0.84380000 0.00000000 0.00000000 0.00000000
0.77311000 0.46150000 0.84380000 0.00000000 0.00000000 0.00000000
0.22689000 0.53850000 0.34380000 0.00000000 0.00000000 0.00000000
0.79407000 0.79920000 0.35690000 0.00000000 0.00000000 0.00000000
0.20593000 0.20080000 0.85690000 0.00000000 0.00000000 0.00000000
0.70593000 0.29920000 0.85690000 0.00000000 0.00000000 0.00000000
0.29407000 0.70080000 0.35690000 0.00000000 0.00000000 0.00000000
0.80420000 0.62110000 0.27560000 0.00000000 0.00000000 0.00000000
0.19580000 0.37890000 0.77560000 0.00000000 0.00000000 0.00000000
0.69580000 0.12110000 0.77560000 0.00000000 0.00000000 0.00000000
0.30420000 0.87890000 0.27560000 0.00000000 0.00000000 0.00000000
0.74710000 0.60800000 0.17700000 0.00000000 0.00000000 0.00000000
0.25290000 0.39200000 0.67700000 0.00000000 0.00000000 0.00000000
0.75290000 0.10800000 0.67700000 0.00000000 0.00000000 0.00000000
0.24710000 0.89200000 0.17700000 0.00000000 0.00000000 0.00000000
0.61160000 0.79860000 0.06370000 0.00000000 0.00000000 0.00000000
0.38840000 0.20140000 0.56370000 0.00000000 0.00000000 0.00000000
0.88840000 0.29860000 0.56370000 0.00000000 0.00000000 0.00000000
0.11160000 0.70140000 0.06370000 0.00000000 0.00000000 0.00000000
0.55830000 0.00840000 0.10250000 0.00000000 0.00000000 0.00000000
0.44170000 0.99160000 0.60250000 0.00000000 0.00000000 0.00000000
0.94170000 0.50840000 0.60250000 0.00000000 0.00000000 0.00000000
0.05830000 0.49160000 0.10250000 0.00000000 0.00000000 0.00000000
0.59276000 0.09180000 0.21200000 0.00000000 0.00000000 0.00000000
0.40724000 0.90820000 0.71200000 0.00000000 0.00000000 0.00000000
0.90724000 0.59180000 0.71200000 0.00000000 0.00000000 0.00000000
0.09276000 0.40820000 0.21200000 0.00000000 0.00000000 0.00000000
0.66916000 0.94840000 0.24680000 0.00000000 0.00000000 0.00000000
0.33084000 0.05160000 0.74680000 0.00000000 0.00000000 0.00000000
0.83084000 0.44840000 0.74680000 0.00000000 0.00000000 0.00000000
0.16916000 0.55160000 0.24680000 0.00000000 0.00000000 0.00000000
0.68059000 0.77090000 0.16270000 0.00000000 0.00000000 0.00000000
0.31941000 0.22910000 0.66270000 0.00000000 0.00000000 0.00000000
0.81941000 0.27090000 0.66270000 0.00000000 0.00000000 0.00000000
0.18059000 0.72910000 0.16270000 0.00000000 0.00000000 0.00000000
'N.in' : spfname
4 : natoms; atposl, bfcmt below
0.37630000 0.42680000 0.04850000 0.00000000 0.00000000 0.00000000
0.62370000 0.57320000 0.54850000 0.00000000 0.00000000 0.00000000
0.12370000 0.92680000 0.54850000 0.00000000 0.00000000 0.00000000
0.87630000 0.07320000 0.04850000 0.00000000 0.00000000 0.00000000
ngridk
6 8 7
plot1d
13 1000 : nvp1d, npp1d
0.0 0.0 0.0 ~G : vlvp1d
0.5 0.0 0.0 X
0.5 0.0 0.5 U
0.0 0.0 0.5 Z
0.0 0.0 0.0 ~G
0.0 0.5 0.0 Y
0.5 0.5 0.0 S
0.5 0.0 0.0 X
0.0 0.0 0.0 ~G
0.0 0.0 0.5 Z
0.0 0.5 0.5 T
0.0 0.5 0.0 Y
0.0 0.0 0.0 ~G
vkloff
0.5 0.5 0.5
==========================================================================
please help me as soon as possible.
thanks
Looks like the default value of energy grid is used. Please use
dos
1000 100 1
0.0 0.5
and run just the options 121 and 320 again.
Dear sharma
I wish best times for you. thank you very much.
best regards
Dr. Sharma will know better, but I believe you need a nonzero G vector for the response function. gmaxrf=1.5 or so. This will greatly increase computational expense (memory I believe mostly) but I believe if you have gmaxrf=0 you are still going to get the RPA results as LFE are not included.
Best
With bootstrap kernel (fxctype=210), even with gmaxrf=0 the results include excitonic effects and should be different from RPA results (if material has excitons).
Increasing gmaxrf will include local field efects. In most cases these effects are quite small.