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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