[QE-users] Inconsistency | It seems that omega_ln is in the unit of meV rather than K
Jibiao Li
jibiaoli at foxmail.com
Wed May 5 04:30:32 CEST 2021
Dear Mitsuaki,
Thank you very much for pointing out the crux. I just realize that the structure is not stable under high pressure. Things are different from the cubic H3S structure without the carbon replacement.
Sincerely
Dr. Jibiao Li,
Department of Material Science and Engineering
Yangtze Normal University
Juxian Dadao 16#, Fuling, Chongqing, China
Email: jibiaoli at yznu.edu.cn, jibiaoli at foxmail.com, jibiao.li at hotmail.com
Homepage: https://www.researchgate.net/profile/Jibiao_Li
------------------ Original ------------------
From: "Quantum ESPRESSO users Forum" <mkawamura at issp.u-tokyo.ac.jp>;
Date: Tue, May 4, 2021 09:23 PM
To: "'Quantum ESPRESSO users Forum'"<users at lists.quantum-espresso.org>;
Subject: Re: [QE-users] Inconsistency | It seems that omega_ln is in the unit of meV rather than K
Dear Dr. Jibiao Li
I performed the calculation by using your input files.
At the first q point [q = (0.0, 0.0, 0.0)], I obtained six imaginary
frequencies as follows:
freq ( 1) = -64.626507 [THz] = -2155.708217 [cm-1]
freq ( 2) = -64.626507 [THz] = -2155.708217 [cm-1]
freq ( 3) = -64.626507 [THz] = -2155.708217 [cm-1]
freq ( 4) = -1.506110 [THz] = -50.238408 [cm-1]
freq ( 5) = -1.506110 [THz] = -50.238408 [cm-1]
freq ( 6) = -1.506110 [THz] = -50.238408 [cm-1]
freq ( 7) = 1.768616 [THz] = 58.994680 [cm-1]
:
Is it the same as your result?
I guess this structure is unstable.
It is better to relax the structure first.
Best regards,
Mitsuaki Kawamura
Institute for Solid State Physics, The University of Tokyo
Materials Design and Characterization Laboratory
Mitsuaki Kawamura
mkawamura at issp.u-tokyo.ac.jp
From: users <users-bounces at lists.quantum-espresso.org> On Behalf Of Jibiao
Li
Sent: Tuesday, May 4, 2021 4:24 PM
To: users <users at lists.quantum-espresso.org>
Subject: [QE-users] Inconsistency | It seems that omega_ln is in the unit of
meV rather than K
Dear All,
I am trying to calculate Tc of the C-S-H system by simply replacing one S
atom by one C atom in the cubic cell. Followed by the instruction by Dr.
Mitsuaki Kawamura, I computed lambda and omega_ln with matdyn.x by using the
tetrahedron method (see the inputs).
However, I found the Tc would be too small if we take the unit of omega_ln
in Kelvin when comparing the outcome with that in references. On the
contrary, it would be more reasonable to treat it in the unit of meV. Is
omega_ln truly in Kelvin? What's wrong with my calcualtions?
CHS: lambda=1.25, omega_ln=137.33 (K??) Tc=Too small
H3S: lambda=1.31, omega_log=127.93 meV, Tc=164 K (Scientific Reports 7,
4473 (2017))
H3S: lambda=2.41, omega_log=109.00 meV, Tc=255 K (Eur. Phys. J. B 89, 63
(2016))
H3S: lambda=2.58, omega_log=1336.0 K, Tc=267 K (Phys. Rev. B 91, 224513
(2015))
scf.inp(pw.x input)
&CONTROL
calculation = 'scf' ,
restart_mode = 'from_scratch' ,
outdir = './' ,
pseudo_dir = '/home/jibiaoli/pseudo/PAW' ,
prefix = 'bulk' ,
/
&SYSTEM
ibrav = 1,
celldm(1) = 5.365696156,
nat = 8,
ntyp = 3,
ecutwfc = 45 ,
ecutrho = 591 ,
occupations = 'tetrahedra_opt' ,
vdw_corr = 'grimme-d2' ,
/
&ELECTRONS
electron_maxstep = 299,
mixing_beta = 0.2D0 ,
diagonalization = 'david' ,
/
ATOMIC_SPECIES
C 12.01000 C.pbe-n-kjpaw_psl.1.0.0.UPF
H 1.00794 H.pbe-kjpaw_psl.1.0.0.UPF
S 32.06500 S.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS angstrom
H 1.419701496 1.419701496 0.000000000
H 0.000000000 1.419701496 0.000000000
H 1.419701496 0.000000000 0.000000000
H 0.000000000 1.419701496 1.419701496
H 0.000000000 0.000000000 1.419701496
H 1.419701496 0.000000000 1.419701496
C 1.419701496 1.419701496 1.419701496
S 0.000000000 -0.000000000 0.000000000
K_POINTS automatic
12 12 12 0 0 0
ph.inp (ph.x input)
Phonon for CSH
&inputph
search_sym = .false.,
tr2_ph = 1.0d-14,
prefix = 'bulk',
fildvscf = 'aldv',
amass(1) = 12.0100,
amass(2) = 1.00794,
amass(3) = 32.0650,
outdir = './',
fildyn = 'bulk.dyn',
ldisp = .true.,
nq1 = 12, nq2 = 12, nq3 = 12,
/
elph.inp (ph.x input)
Electron-Phonon coefficients for CSH
&inputph
search_sym = .false.,
tr2_ph = 1.0d-14,
prefix = 'bulk',
fildvscf = 'aldv',
amass(1) = 12.0100,
amass(2) = 1.00794,
amass(3) = 32.0650,
outdir = './',
fildyn = 'bulk.dyn',
electron_phonon = 'lambda_tetra',
ldisp = .true.,
nq1 = 12, nq2 = 12, nq3 = 12,
nk1 = 24, nk2 = 24, nk3 = 24,
/
q2r.in
&input
zasr='simple', fildyn='bulk.dyn', flfrc='bulk121212.fc', la2F=.true.
/
matdyn.in.freq
&input
asr='simple', amass(1) = 12.0100, amass(2) = 1.00794,amass(3) =
32.0650,
flfrc='bulk121212.fc', flfrq='bulk1212112.freq', la2F=.true.,
dos=.false.
/
19
0.000 0.0 0.0 0.0
0.125 0.0 0.0 0.0
0.250 0.0 0.0 0.0
0.375 0.0 0.0 0.0
0.500 0.0 0.0 0.0
0.750 0.0 0.0 0.0
1.000 0.0 0.0 0.0
0.825 0.125 0.125 0.0
0.750 0.250 0.250 0.0
0.625 0.375 0.375 0.0
0.500 0.500 0.500 0.0
0.325 0.325 0.325 0.0
0.250 0.250 0.250 0.0
0.125 0.125 0.125 0.0
0.000 0.000 0.000 0.0
0.125 0.125 0.000 0.0
0.250 0.250 0.000 0.0
0.325 0.325 0.000 0.0
0.500 0.500 0.000 0.0
matdyn.in.dos
&input
asr='simple', amass(1) = 12.0100, amass(2) = 1.00794, amass(3) =
32.0650,
flfrc='bulk121212.fc', flfrq='bulk121212.freq', la2F=.true., dos=.true.
fldos='phonon.dos', nk1=12, nk2=12, nk3=12, ndos=100
/
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