<meta http-equiv="Content-Type" content="text/html; charset=GB18030"><div>Dear Mitsuaki,</div><div>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.</div><div><br></div><div>Sincerely</div><div><br></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Dr. Jibiao Li,</b></font></i></div><div><div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Department of Material Science and Engineering</b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Yangtze Normal University</b></font></i></div><div><i><font face="Times New Roman"><font size="2"><font color="#0000ff"><b><span style="line-height: 21px; font-variant-numeric: normal; font-variant-east-asian: normal; background-color: transparent;">Juxian Dadao 16#,</span> Fuling, Chongqing, China</b></font></font></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Email: jibiaoli@yznu.edu.cn, jibiaoli@foxmail.com, jibiao.li@hotmail.com</b></font></i></div><div><i><font color="#0000ff" face="Times New Roman" size="2"><b>Homepage: https://www.researchgate.net/profile/Jibiao_Li</b></font></i></div></div><div><br></div><div style="font-size: 12px;font-family: Arial Narrow;padding:2px 0 2px 0;">------------------ Original ------------------</div><div style="font-size: 12px;background:#efefef;padding:8px;"><div><b>From:</b> "Quantum ESPRESSO users Forum" <mkawamura@issp.u-tokyo.ac.jp>;</div><div><b>Date:</b> Tue, May 4, 2021 09:23 PM</div><div><b>To:</b> "'Quantum ESPRESSO users Forum'"<users@lists.quantum-espresso.org>;<wbr></div><div></div><div><b>Subject:</b> Re: [QE-users] Inconsistency | It seems that omega_ln is in the unit of meV rather than K</div></div><div><br></div>Dear Dr. Jibiao Li<br><br>I performed the calculation by using your input files.<br>At the first q point [q = (0.0, 0.0, 0.0)], I obtained six imaginary<br>frequencies as follows:<br> freq ( 1) = -64.626507 [THz] = -2155.708217 [cm-1]<br> freq ( 2) = -64.626507 [THz] = -2155.708217 [cm-1]<br> freq ( 3) = -64.626507 [THz] = -2155.708217 [cm-1]<br> freq ( 4) = -1.506110 [THz] = -50.238408 [cm-1]<br> freq ( 5) = -1.506110 [THz] = -50.238408 [cm-1]<br> freq ( 6) = -1.506110 [THz] = -50.238408 [cm-1]<br> freq ( 7) = 1.768616 [THz] = 58.994680 [cm-1]<br> :<br>Is it the same as your result?<br><br>I guess this structure is unstable.<br>It is better to relax the structure first.<br><br>Best regards,<br>Mitsuaki Kawamura<br><br>Institute for Solid State Physics, The University of Tokyo<br>Materials Design and Characterization Laboratory<br>Mitsuaki Kawamura<br>mkawamura@issp.u-tokyo.ac.jp<br><br>From: users <users-bounces@lists.quantum-espresso.org> On Behalf Of Jibiao<br>Li<br>Sent: Tuesday, May 4, 2021 4:24 PM<br>To: users <users@lists.quantum-espresso.org><br>Subject: [QE-users] Inconsistency | It seems that omega_ln is in the unit of<br>meV rather than K<br><br>Dear All, <br><br>I am trying to calculate Tc of the C-S-H system by simply replacing one S<br>atom by one C atom in the cubic cell. Followed by the instruction by Dr.<br>Mitsuaki Kawamura, I computed lambda and omega_ln with matdyn.x by using the<br>tetrahedron method (see the inputs).<br><br>However, I found the Tc would be too small if we take the unit of omega_ln<br>in Kelvin when comparing the outcome with that in references. On the<br>contrary, it would be more reasonable to treat it in the unit of meV. Is<br>omega_ln truly in Kelvin? What's wrong with my calcualtions?<br><br>CHS: lambda=1.25, omega_ln=137.33 (K??) Tc=Too small <br>H3S: lambda=1.31, omega_log=127.93 meV, Tc=164 K (Scientific Reports 7,<br>4473 (2017))<br>H3S: lambda=2.41, omega_log=109.00 meV, Tc=255 K (Eur. Phys. J. B 89, 63<br>(2016))<br>H3S: lambda=2.58, omega_log=1336.0 K, Tc=267 K (Phys. Rev. B 91, 224513<br>(2015))<br><br><br>scf.inp(pw.x input)<br> &CONTROL<br> calculation = 'scf' ,<br> restart_mode = 'from_scratch' ,<br> outdir = './' ,<br> pseudo_dir = '/home/jibiaoli/pseudo/PAW' ,<br> prefix = 'bulk' ,<br> /<br> &SYSTEM<br> ibrav = 1,<br> celldm(1) = 5.365696156,<br> nat = 8,<br> ntyp = 3,<br> ecutwfc = 45 ,<br> ecutrho = 591 ,<br> occupations = 'tetrahedra_opt' ,<br> vdw_corr = 'grimme-d2' ,<br> /<br> &ELECTRONS<br> electron_maxstep = 299,<br> mixing_beta = 0.2D0 ,<br> diagonalization = 'david' ,<br> /<br>ATOMIC_SPECIES<br> C 12.01000 C.pbe-n-kjpaw_psl.1.0.0.UPF<br> H 1.00794 H.pbe-kjpaw_psl.1.0.0.UPF<br> S 32.06500 S.pbe-n-kjpaw_psl.1.0.0.UPF<br>ATOMIC_POSITIONS angstrom<br>H 1.419701496 1.419701496 0.000000000<br>H 0.000000000 1.419701496 0.000000000<br>H 1.419701496 0.000000000 0.000000000<br>H 0.000000000 1.419701496 1.419701496<br>H 0.000000000 0.000000000 1.419701496<br>H 1.419701496 0.000000000 1.419701496<br>C 1.419701496 1.419701496 1.419701496<br>S 0.000000000 -0.000000000 0.000000000<br>K_POINTS automatic<br> 12 12 12 0 0 0<br><br>ph.inp (ph.x input)<br>Phonon for CSH<br>&inputph<br>search_sym = .false.,<br>tr2_ph = 1.0d-14,<br>prefix = 'bulk',<br>fildvscf = 'aldv',<br>amass(1) = 12.0100,<br>amass(2) = 1.00794,<br>amass(3) = 32.0650,<br>outdir = './',<br>fildyn = 'bulk.dyn',<br>ldisp = .true.,<br>nq1 = 12, nq2 = 12, nq3 = 12,<br>/<br><br>elph.inp (ph.x input)<br>Electron-Phonon coefficients for CSH<br>&inputph<br>search_sym = .false.,<br>tr2_ph = 1.0d-14,<br>prefix = 'bulk',<br>fildvscf = 'aldv',<br>amass(1) = 12.0100,<br>amass(2) = 1.00794,<br>amass(3) = 32.0650,<br>outdir = './',<br>fildyn = 'bulk.dyn',<br>electron_phonon = 'lambda_tetra',<br>ldisp = .true.,<br>nq1 = 12, nq2 = 12, nq3 = 12,<br>nk1 = 24, nk2 = 24, nk3 = 24,<br>/<br>q2r.in<br> &input<br> zasr='simple', fildyn='bulk.dyn', flfrc='bulk121212.fc', la2F=.true.<br> /<br><br>matdyn.in.freq<br> &input<br> asr='simple', amass(1) = 12.0100, amass(2) = 1.00794,amass(3) =<br>32.0650,<br> flfrc='bulk121212.fc', flfrq='bulk1212112.freq', la2F=.true.,<br>dos=.false.<br> /<br> 19<br> 0.000 0.0 0.0 0.0<br> 0.125 0.0 0.0 0.0<br> 0.250 0.0 0.0 0.0<br> 0.375 0.0 0.0 0.0<br> 0.500 0.0 0.0 0.0<br> 0.750 0.0 0.0 0.0<br> 1.000 0.0 0.0 0.0<br> 0.825 0.125 0.125 0.0<br> 0.750 0.250 0.250 0.0<br> 0.625 0.375 0.375 0.0<br> 0.500 0.500 0.500 0.0<br> 0.325 0.325 0.325 0.0<br> 0.250 0.250 0.250 0.0<br> 0.125 0.125 0.125 0.0<br> 0.000 0.000 0.000 0.0<br> 0.125 0.125 0.000 0.0<br> 0.250 0.250 0.000 0.0<br> 0.325 0.325 0.000 0.0<br> 0.500 0.500 0.000 0.0<br><br>matdyn.in.dos<br> &input<br> asr='simple', amass(1) = 12.0100, amass(2) = 1.00794, amass(3) =<br>32.0650,<br> flfrc='bulk121212.fc', flfrq='bulk121212.freq', la2F=.true., dos=.true.<br> fldos='phonon.dos', nk1=12, nk2=12, nk3=12, ndos=100<br> /<br><br>_______________________________________________<br>Quantum ESPRESSO is supported by MaX (www.max-centre.eu)<br>users mailing list users@lists.quantum-espresso.org<br>https://lists.quantum-espresso.org/mailman/listinfo/users<br><div><br></div><div><hr align="left" style="margin: 0 0 10px 0;border: 0;border-bottom:1px solid #E4E5E6;height:0;line-height:0;font-size:0;padding: 20px 0 0 0;width: 50px;"><div style="font-size:14px;font-family:Verdana;color:#000;"><div><br></div>
</div></div></div>