I am Seungjun Lee, I am interested in electron imaginary self energy (electron relaxation time)
I am using EPW 4.0.0 version and lastest version QE.
I want to calculate optical and acoustic phonon mode contribution of electron imaginary self energy.
So, I try some test using eps_acustic option.
(I understand that eps_acustic option set lower boundary of phonon frequency of input data, Is it right?)
I try to tested 2 cases, silicone and phosphorene.
First, I run EPW without eps_acustic option, (defalut : 5 cm-1) - (1)
next, I run EPW with eps_acustic option each cases. - (2)
and then, I calculate optical mode contribution using (2) / (1)
From my result, silicone cases, optical mode has 50% contribution of electron imaginary self energy. (set eps_acustic : 400 cm-1)
phosphorene cases, optical mode has 90% contribution of electron imaginary self energy. (set eps_acustic : 200 cm-1, This result is similar to PHYSICAL REVIEW B 91, 235419 (2015) )
Then, I have two questions about eps_acustic.
First, This method is right?
If my method was right, my results are some strange.
In non-polar materials, acoustic phonon mode is dominated in electron - phonon scattering.
So, I cannot understand my result.
How can I understand this result?
attached my input file
thank you.
Best Regards,
Seungjun Lee
Code: Select all
--
&inputepw
prefix = 'Si'
amass(1) = 28.0885
outdir = './'
iverbosity = 0
elph = .true.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.
nbndsub = 8
nbndskip = 0
wannierize = .true.
num_iter = 1000
iprint = 2
dis_win_max = 17
dis_froz_max= 6
proj(1) = 'Si:sp3'
elinterp = .true.
phinterp = .true.
tshuffle2 = .true.
tphases = .false.
elecselfen = .ture.
phonselfen = .false.
a2f = .false.
parallel_k = .true.
parallel_q = .false.
fsthick = 15 ! eV
eptemp = 300 ! K (same as PRB 76, 165108)
degaussw = 1.0 ! eV
eps_acustic = 400
dvscf_dir = './save'
filukk = './Si.ukk'
filkf = './mesh.dat'
! nkf1 = 20
! nkf2 = 20
! nkf3 = 20
nqf1 = 50
nqf2 = 50
nqf3 = 50
nk1 = 6
nk2 = 6
nk3 = 6
nq1 = 6
nq2 = 6
nq3 = 6
/
16 cartesian
0.0000000 0.0000000 0.0000000 0.0092593
-0.1666667 0.1666667 -0.1666667 0.0740741
-0.3333333 0.3333333 -0.3333333 0.0740741
0.5000000 -0.5000000 0.5000000 0.0370370
0.0000000 0.3333333 0.0000000 0.0555556
-0.1666667 0.5000000 -0.1666667 0.2222222
0.6666667 -0.3333333 0.6666667 0.2222222
0.5000000 -0.1666667 0.5000000 0.2222222
0.3333333 0.0000000 0.3333333 0.1111111
0.0000000 0.6666667 0.0000000 0.0555556
0.8333333 -0.1666667 0.8333333 0.2222222
0.6666667 0.0000000 0.6666667 0.1111111
0.0000000 -1.0000000 0.0000000 0.0277778
0.6666667 -0.3333333 1.0000000 0.2222222
0.5000000 -0.1666667 0.8333333 0.2222222
-0.3333333 -1.0000000 0.0000000 0.1111111Code: Select all
--
&inputepw
prefix = 'P'
amass(1) = 30.9738
outdir = './'
iverbosity = 0
elph = .true.
epbwrite = .true.
epbread = .false.
epwwrite = .true.
epwread = .false.
nbndsub = 16
nbndskip = 0
wannierize = .true.
num_iter = 2000
iprint = 2
! dis_win_max = 12
! dis_froz_max= 7
proj(1) = 'P:sp3'
wdata(1) = 'dis_num_iter = 2000'
wdata(2) = 'guiding_centres = ture'
elinterp = .true.
phinterp = .true.
tshuffle2 = .true.
tphases = .false.
elecselfen = .true.
phonselfen = .false.
a2f = .false.
eps_acustic = 200
parallel_k = .true.
parallel_q = .false.
fsthick = 20 ! eV
eptemp = 300 ! K (same as PRB 76, 165108)
degaussw = 0.01 ! eV
dvscf_dir = './save/'
filukk = './P.ukk'
filkf = './mesh.dat'
nqf1 = 50
nqf2 = 50
nqf3 = 1
nk1 = 10
nk2 = 10
nk3 = 1
nq1 = 10
nq2 = 10
nq3 = 1
/
36 cartesian
0.0000000 0.0000000 0.0000000 0.0200000
0.0000000 0.1404281 0.0000000 0.0400000
0.0000000 0.2808562 0.0000000 0.0400000
0.0000000 0.4212842 0.0000000 0.0400000
0.0000000 0.5617123 0.0000000 0.0400000
0.0000000 -0.7021404 0.0000000 0.0200000
0.1000000 0.0000000 0.0000000 0.0400000
0.1000000 0.1404281 0.0000000 0.0800000
0.1000000 0.2808562 0.0000000 0.0800000
0.1000000 0.4212842 0.0000000 0.0800000
0.1000000 0.5617123 0.0000000 0.0800000
0.1000000 -0.7021404 0.0000000 0.0400000
0.2000000 0.0000000 0.0000000 0.0400000
0.2000000 0.1404281 0.0000000 0.0800000
0.2000000 0.2808562 0.0000000 0.0800000
0.2000000 0.4212842 0.0000000 0.0800000
0.2000000 0.5617123 0.0000000 0.0800000
0.2000000 -0.7021404 0.0000000 0.0400000
0.3000000 0.0000000 0.0000000 0.0400000
0.3000000 0.1404281 0.0000000 0.0800000
0.3000000 0.2808562 0.0000000 0.0800000
0.3000000 0.4212842 0.0000000 0.0800000
0.3000000 0.5617123 0.0000000 0.0800000
0.3000000 -0.7021404 0.0000000 0.0400000
0.4000000 0.0000000 0.0000000 0.0400000
0.4000000 0.1404281 0.0000000 0.0800000
0.4000000 0.2808562 0.0000000 0.0800000
0.4000000 0.4212842 0.0000000 0.0800000
0.4000000 0.5617123 0.0000000 0.0800000
0.4000000 -0.7021404 0.0000000 0.0400000
-0.5000000 0.0000000 0.0000000 0.0200000
-0.5000000 0.1404281 0.0000000 0.0400000
-0.5000000 0.2808562 0.0000000 0.0400000
-0.5000000 0.4212842 0.0000000 0.0400000
-0.5000000 0.5617123 0.0000000 0.0400000
-0.5000000 -0.7021404 0.0000000 0.0200000