Dear users and developers, I am using QE v7.0 and trying to investigate the superconductivity of a 2D material. I have used the PBE pseudopotential from PSlibrary and took Kmesh 36x36x1. After vc-relax, the resulted forces and stress are:
*Total force = 0.000014 Total SCF correction = 0.000001 Computing stress (Cartesian axis) and pressure negative rho (up, down): 1.001E-01 0.000E+00 total stress (Ry/bohr**3) (kbar) P= -0.10* Are these values acceptable? Do I need to reduce these values? Here a typical ph.in file I use: *title_line&inputph prefix = 'W2F2', fildyn = 'W2F2.dyn', amass(1) = 18.9984032, amass(2) = 183.84, outdir = './' ldisp = .true., trans = .true., fildvscf = 'dvscf', search_sym=.FALSE., alpha_mix(1) = 0.2, nq1=3, nq2=3, nq3=1, tr2_ph = 1.0d-12/* When I ran ph.in by adding "*alpha_mix flag"*, I am getting* no imaginary frequencies*, but the lambda.out file shows NaN *lambda = 0.835778 ( NaN ) <log w>= NaN K N(Ef)= 11.024689 at degauss= 0.005 lambda = 0.598189 ( NaN ) <log w>= NaN K N(Ef)= 10.196114 at degauss= 0.010 lambda = 0.526611 ( NaN ) <log w>= NaN K N(Ef)= 9.481577 at degauss= 0.015 lambda = 0.485222 ( NaN ) <log w>= NaN K N(Ef)= 8.817546 at degauss= 0.020 lambda = 0.465900 ( NaN ) <log w>= NaN K N(Ef)= 8.336884 at degauss= 0.025 lambda = 0.466822 ( NaN ) <log w>= NaN K N(Ef)= 8.111690 at degauss= 0.030 lambda = 0.481500 ( NaN ) <log w>= NaN K N(Ef)= 8.111006 at degauss= 0.035 lambda = 0.504944 ( NaN ) <log w>= NaN K N(Ef)= 8.267627 at degauss= 0.040 lambda = 0.532578 ( NaN ) <log w>= NaN K N(Ef)= 8.520600 at degauss= 0.045 lambda = 0.562378 ( NaN ) <log w>= NaN K N(Ef)= 8.823055 at degauss= 0.050lambda omega_log T_c 0.83578 NaN NaN 0.59819 NaN NaN 0.52661 NaN NaN 0.48522 NaN NaN 0.46590 NaN NaN 0.46682 NaN NaN 0.48150 NaN NaN 0.50494 NaN NaN 0.53258 NaN NaN* * 0.56238 NaN NaN* And when I ran ph.in *without alpha_mix flag*, there were imaginary frequencies in the phonon dispersion and I am getting values in lambda.out file *lambda = 0.760811 ( 0.760801 ) <log w>= 197.892 K N(Ef)= 11.024689 at degauss= 0.005 lambda = 0.573322 ( 0.573317 ) <log w>= 188.429 K N(Ef)= 10.196114 at degauss= 0.010 lambda = 0.520900 ( 0.520896 ) <log w>= 184.554 K N(Ef)= 9.481577 at degauss= 0.015 lambda = 0.488111 ( 0.488108 ) <log w>= 183.224 K N(Ef)= 8.817546 at degauss= 0.020 lambda = 0.474378 ( 0.474375 ) <log w>= 182.309 K N(Ef)= 8.336884 at degauss= 0.025 lambda = 0.481178 ( 0.481175 ) <log w>= 181.389 K N(Ef)= 8.111690 at degauss= 0.030 lambda = 0.502378 ( 0.502375 ) <log w>= 180.618 K N(Ef)= 8.111006 at degauss= 0.035 lambda = 0.533389 ( 0.533386 ) <log w>= 180.243 K N(Ef)= 8.267627 at degauss= 0.040 lambda = 0.569867 ( 0.569863 ) <log w>= 180.075 K N(Ef)= 8.520600 at degauss= 0.045 lambda = 0.608489 ( 0.608486 ) <log w>= 180.009 K N(Ef)= 8.823055 at degauss= 0.050* *lambda omega_log T_c 0.76081 197.892 7.177 0.57332 188.429 2.921 0.52090 184.554 1.950 0.48811 183.224 1.439 0.47438 182.309 1.243 0.48118 181.389 1.329 0.50238 180.618 1.624 0.53339 180.243 2.106 0.56987 180.075 2.730 0.60849 180.009 3.443* Could anyone tell me what was going wrong here. Kindly help me to fix this. Thank you. Regards Prarena Jamwal Research Scholar IIT Ropar, INDIA. -- **CONFIDENTIALITY NOTICE: The contents of this email message and any attachments are intended solely for the addressee(s) and may contain confidential and/or privileged information and may be legally protected from disclosure. If you are not the intended recipient of this message or their agent, or if this message has been addressed to you in error, please immediately alert the sender by reply email and then delete this message and any attachments. If you are not the intended recipient, you are hereby notified that any use, dissemination, copying, or storage of this message or its attachments is strictly prohibited.* *
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