<meta http-equiv="Content-Type" content="text/html; charset=GB18030"><div><div>Dear All, </div><div><br></div><div>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. <span style="  ; ; ;; ">Mitsuaki Kawamura, I computed</span> lambda and omega_ln with matdyn.x by using the tetrahedron method (see the inputs).</div><div><br></div><div>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?</div><div><br></div><div><span style="   ;;  ">CHS: lambda=1.25, omega_ln=</span><span style="   ;;  ">137.33 (K??)  Tc=Too small </span><br style="   ;;  ">H3S: lambda=1.31, omega_log=127.93 meV, Tc=164 K  (Scientific Reports 7, 4473 (2017))</div><div>H3S: lambda=2.41, omega_log=109.00 meV, Tc=255 K  (Eur. Phys. J. B 89, 63 (2016))</div><div>H3S: lambda=2.58, omega_log=1336.0 K,     Tc=267 K  (Phys. Rev. B 91, 224513 (2015))</div></div><div><span style="   ;;  "><br></span></div><div><br style="   ;;  "><span style="   ;;  ">scf.inp(pw.x input)</span><br style="   ;;  "><span style="   ;;  "> &CONTROL</span><br style="   ;;  "><span style="   ;;  ">                 calculation = 'scf' ,</span><br style="   ;;  "><span style="   ;;  ">                restart_mode = 'from_scratch' ,</span><br style="   ;;  "><span style="   ;;  ">                      outdir = './' ,</span><br style="   ;;  "><span style="   ;;  ">                  pseudo_dir = '/home/jibiaoli/pseudo/PAW' ,</span><br style="   ;;  "><span style="   ;;  ">                      prefix = 'bulk' ,</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "><span style="   ;;  "> &SYSTEM</span><br style="   ;;  "><span style="   ;;  ">                       ibrav = 1,</span><br style="   ;;  "><span style="   ;;  ">                   celldm(1) = 5.365696156,</span><br style="   ;;  "><span style="   ;;  ">                         nat = 8,</span><br style="   ;;  "><span style="   ;;  ">                        ntyp = 3,</span><br style="   ;;  "><span style="   ;;  ">                     ecutwfc = 45 ,</span><br style="   ;;  "><span style="   ;;  ">                     ecutrho = 591 ,</span><br style="   ;;  "><span style="   ;;  ">                 occupations = 'tetrahedra_opt' ,</span><br style="   ;;  "><span style="   ;;  ">                    vdw_corr = 'grimme-d2' ,</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "><span style="   ;;  "> &ELECTRONS</span><br style="   ;;  "><span style="   ;;  ">            electron_maxstep = 299,</span><br style="   ;;  "><span style="   ;;  ">                 mixing_beta = 0.2D0 ,</span><br style="   ;;  "><span style="   ;;  ">             diagonalization = 'david' ,</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "><span style="   ;;  ">ATOMIC_SPECIES</span><br style="   ;;  "><span style="   ;;  ">    C   12.01000  C.pbe-n-kjpaw_psl.1.0.0.UPF</span><br style="   ;;  "><span style="   ;;  ">    H    1.00794  H.pbe-kjpaw_psl.1.0.0.UPF</span><br style="   ;;  "><span style="   ;;  ">    S   32.06500  S.pbe-n-kjpaw_psl.1.0.0.UPF</span><br style="   ;;  "><span style="   ;;  ">ATOMIC_POSITIONS angstrom</span><br style="   ;;  "><span style="   ;;  ">H        1.419701496   1.419701496   0.000000000</span><br style="   ;;  "><span style="   ;;  ">H        0.000000000   1.419701496   0.000000000</span><br style="   ;;  "><span style="   ;;  ">H        1.419701496   0.000000000   0.000000000</span><br style="   ;;  "><span style="   ;;  ">H        0.000000000   1.419701496   1.419701496</span><br style="   ;;  "><span style="   ;;  ">H        0.000000000   0.000000000   1.419701496</span><br style="   ;;  "><span style="   ;;  ">H        1.419701496   0.000000000   1.419701496</span><br style="   ;;  "><span style="   ;;  ">C        1.419701496   1.419701496   1.419701496</span><br style="   ;;  "><span style="   ;;  ">S        0.000000000  -0.000000000   0.000000000</span><br style="   ;;  "><span style="   ;;  ">K_POINTS automatic</span><br style="   ;;  "><span style="   ;;  ">  12 12 12   0 0 0</span><br style="   ;;  "><br style="   ;;  "><span style="   ;;  ">ph.inp (ph.x input)</span><br style="   ;;  "><span style="   ;;  ">Phonon for CSH</span><br style="   ;;  "><span style="   ;;  ">&inputph</span><br style="   ;;  "><span style="   ;;  ">search_sym = .false.,</span><br style="   ;;  "><span style="   ;;  ">tr2_ph = 1.0d-14,</span><br style="   ;;  "><span style="   ;;  ">prefix = 'bulk',</span><br style="   ;;  "><span style="   ;;  ">fildvscf = 'aldv',</span><br style="   ;;  "><span style="   ;;  ">amass(1) = 12.0100,</span><br style="   ;;  "><span style="   ;;  ">amass(2) = 1.00794,</span><br style="   ;;  "><span style="   ;;  ">amass(3) = 32.0650,</span><br style="   ;;  "><span style="   ;;  ">outdir = './',</span><br style="   ;;  "><span style="   ;;  ">fildyn = 'bulk.dyn',</span><br style="   ;;  "><span style="   ;;  ">ldisp = .true.,</span><br style="   ;;  "><span style="   ;;  ">nq1 = 12, nq2 = 12, nq3 = 12,</span><br style="   ;;  "><span style="   ;;  ">/</span><br style="   ;;  "><br style="   ;;  "><span style="   ;;  ">elph.inp (ph.x input)</span><br style="   ;;  "><span style="   ;;  ">Electron-Phonon coefficients for CSH</span><br style="   ;;  "><span style="   ;;  ">&inputph</span><br style="   ;;  "><span style="   ;;  ">search_sym = .false.,</span><br style="   ;;  "><span style="   ;;  ">tr2_ph = 1.0d-14,</span><br style="   ;;  "><span style="   ;;  ">prefix = 'bulk',</span><br style="   ;;  "><span style="   ;;  ">fildvscf = 'aldv',</span><br style="   ;;  "><span style="   ;;  ">amass(1) = 12.0100,</span><br style="   ;;  "><span style="   ;;  ">amass(2) = 1.00794,</span><br style="   ;;  "><span style="   ;;  ">amass(3) = 32.0650,</span><br style="   ;;  "><span style="   ;;  ">outdir = './',</span><br style="   ;;  "><span style="   ;;  ">fildyn = 'bulk.dyn',</span><br style="   ;;  "><span style="   ;;  ">electron_phonon = 'lambda_tetra',</span><br style="   ;;  "><span style="   ;;  ">ldisp = .true.,</span><br style="   ;;  "><span style="   ;;  ">nq1 = 12, nq2 = 12, nq3 = 12,</span><br style="   ;;  "><span style="   ;;  ">nk1 = 24, nk2 = 24, nk3 = 24,</span><br style="   ;;  "><span style="   ;;  ">/</span><br style="   ;;  "><br></div><div>q2r.in</div><div><span style="   ;;  "> &input</span><br style="   ;;  "><span style="   ;;  ">  zasr='simple',  fildyn='bulk.dyn', flfrc='bulk121212.fc', la2F=.true.</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "><br style="   ;;  "><span style="   ;;  ">matdyn.in.freq</span><br style="   ;;  "><span style="   ;;  "> &input</span><br style="   ;;  "><span style="   ;;  ">    asr='simple',  amass(1) = 12.0100, amass(2) = 1.00794,amass(3) =</span><br style="   ;;  "><span style="   ;;  ">32.0650,</span><br style="   ;;  "><span style="   ;;  ">    flfrc='bulk121212.fc', flfrq='bulk1212112.freq', la2F=.true.,</span><br style="   ;;  "><span style="   ;;  ">dos=.false.</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "><span style="   ;;  ">  19</span><br style="   ;;  "><span style="   ;;  ">  0.000 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.125 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.250 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.375 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.500 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.750 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  1.000 0.0 0.0     0.0</span><br style="   ;;  "><span style="   ;;  ">  0.825 0.125 0.125 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.750 0.250 0.250 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.625 0.375 0.375 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.500 0.500 0.500 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.325 0.325 0.325 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.250 0.250 0.250 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.125 0.125 0.125 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.000 0.000 0.000 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.125 0.125 0.000 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.250 0.250 0.000 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.325 0.325 0.000 0.0</span><br style="   ;;  "><span style="   ;;  ">  0.500 0.500 0.000 0.0</span><br style="   ;;  "><br style="   ;;  "><span style="   ;;  ">matdyn.in.dos</span><br style="   ;;  "><span style="   ;;  "> &input</span><br style="   ;;  "><span style="   ;;  ">    asr='simple',  amass(1) = 12.0100, amass(2) = 1.00794, amass(3) =</span><br style="   ;;  "><span style="   ;;  ">32.0650,</span><br style="   ;;  "><span style="   ;;  ">    flfrc='bulk121212.fc', flfrq='bulk121212.freq', la2F=.true., dos=.true.</span><br style="   ;;  "><span style="   ;;  ">    fldos='phonon.dos', nk1=12, nk2=12, nk3=12, ndos=100</span><br style="   ;;  "><span style="   ;;  "> /</span><br style="   ;;  "></div>