I am trying to calculate the electron-phonon matrix elements |g| using EPW and I am getting all the elements to be zero. Is there any specific reason the g's are zero. There should be any non zero value, however small it is? I am attaching my input file (second step), and in the epw.out they all are zero. Should I manipulate the temperature or anything?
Input
Code: Select all
--
&inputepw
prefix = 'aiida',
amass(1) = 127.6,
amass(2) = 183.84,
outdir = './out/'
elph = .true.
epwwrite = .false.
epwread = .true.
nbndsub = 6,
!nbndskip = 0
bands_skipped = 'exclude_bands = 1:58,65:72'
wannierize = .false.
num_iter = 1000
dis_froz_max= 7.0
dis_froz_min= 2.95
wdata(1) = 'dis_mix_ratio = 0.5'
wdata(2) = 'dis_num_iter = 2000'
wdata(3) = 'bands_plot : true'
wdata(4) = 'bands_num_points : 300'
wdata(5) = 'bands_plot_format : xmgrace gnuplot'
wdata(6) = 'begin kpoint_path'
wdata(7) = 'G 0.0 0.0 0.0 M 0.5 0.0 0.0'
wdata(8) = 'M 0.5 0.0 0.0 K 0.3333 0.3333 0.0'
wdata(9) = 'K 0.3333 0.3333 0.0 G 0.0 0.0 0.0'
wdata(10) = 'end kpoint_path'
wdata(11) = 'write_tb = true'
phonselfen = .true.
delta_approx= .true.
temps = 0.075
degaussw = 0.04 ! eV ~ 1/4 of fsthick
fsthick = 0.2 ! eV ~ 4 times the maximum phonon frequency
prtgkk = .true.
dvscf_dir = '../ph/save'
filqf = 'kpath.dat'
nkf1 = 32
nkf2 = 32
nkf3 = 1
nk1 = 16
nk2 = 16
nk3 = 1
nq1 = 8
nq2 = 8
nq3 = 1
/
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...
ik = 103 coord.: 0.0937500 0.1875000 0.0000000
ibnd jbnd imode enk[eV] enk+q[eV] omega(q)[meV] |g|[meV]
------------------------------------------------------------------------------
3 3 1 5.3677 5.3677 -0.0000002383 0.0000000000E+00
3 3 2 5.3677 5.3677 0.0000002221 0.0000000000E+00
3 3 3 5.3677 5.3677 0.0000005340 0.0000000000E+00
3 3 4 5.3677 5.3677 1.9987083042 0.0000000000E+00
3 3 5 5.3677 5.3677 1.9987083042 0.0000000000E+00
3 3 6 5.3677 5.3677 3.1928043159 0.0000000000E+00
3 3 7 5.3677 5.3677 13.9545962084 0.0000000000E+00
3 3 8 5.3677 5.3677 13.9545962084 0.0000000000E+00
3 3 9 5.3677 5.3677 14.0195163700 0.0000000000E+00
3 3 10 5.3677 5.3677 14.0195163700 0.0000000000E+00
3 3 11 5.3677 5.3677 20.4789381341 0.0000000000E+00
3 3 12 5.3677 5.3677 20.7340609293 0.0000000000E+00
3 3 13 5.3677 5.3677 22.3928677106 0.0000000000E+00
3 3 14 5.3677 5.3677 22.3928677106 0.0000000000E+00
3 3 15 5.3677 5.3677 22.4115456667 0.0000000000E+00
3 3 16 5.3677 5.3677 22.4115456667 0.0000000000E+00
3 3 17 5.3677 5.3677 27.9289851564 0.0000000000E+00
3 3 18 5.3677 5.3677 27.9780553640 0.0000000000E+00
------------------------------------------------------------------------------
ik = 104 coord.: 0.0937500 0.2187500 0.0000000
ibnd jbnd imode enk[eV] enk+q[eV] omega(q)[meV] |g|[meV]
...
Any suggestions would be welcomed.
Thanks,
Shubham