Hi Weilum, I don't have the answer for your question exactly, but could you also share your full elph.in file?
Thanks, Shubham From: "Tang, Weilun [M S E] via users" <[email protected]> To: "users" <[email protected]> Sent: Friday, October 31, 2025 11:55:28 PM Subject: [QE-users] Acoustic Sum Rule Frequency Question Dear Quantum Espresso users, I made a phonon calculation for an isolated molecule using acoustic sum rule asr='zero-dim'. Then, I compared the phonon modes before and after applying the acoustic sum rule. I noticed that there is a mode that has a huge change in frequency, as shown below. More specifically, the 441.1 cm-1 mode seems to be shifted to 115.30 cm-1 after applying the acoustic sum rule. Is this normal? For this calculation, I used lower threshold: forc_conv_thr = 1.0D-6, etot_conv_thr = 1.0D-6, conv_thr = 1.D-14 for pw.x. And for phx, I use tr2_ph=1.0d-18. ------------------------------------------------------------- Below is phonon modes from ph.x: Mode symmetry, D_3h (-62m) point group: freq ( 1- 1) = -27.8 [cm-1] --> A'_2 freq ( 2- 3) = 65.6 [cm-1] --> E'' R freq ( 4- 4) = 103.9 [cm-1] --> A''2 I freq ( 5- 6) = 120.4 [cm-1] --> E'' R freq ( 7- 8) = 146.2 [cm-1] --> E' I+R freq ( 9- 10) = 188.8 [cm-1] --> E' I+R freq ( 11- 11) = 367.1 [cm-1] --> A'_1 R freq ( 12- 13) = 430.7 [cm-1] --> E' I+R freq ( 14- 14) = 441.1 [cm-1] --> A''2 I freq ( 15- 15) = 461.4 [cm-1] --> A'_2 freq ( 16- 17) = 631.9 [cm-1] --> E'' R freq ( 18- 18) = 776.4 [cm-1] --> A''2 I freq ( 19- 20) = 801.0 [cm-1] --> E' I+R freq ( 21- 21) = 907.1 [cm-1] --> A'_1 R freq ( 22- 22) = 1101.1 [cm-1] --> A'_2 freq ( 23- 24) = 1150.0 [cm-1] --> E' I+R freq ( 25- 25) = 1189.0 [cm-1] --> A'_1 R freq ( 26- 27) = 1337.2 [cm-1] --> E' I+R ---------------------------------------------------------------- Below is output from dynmat.x Reading Dynamical Matrix from file dmat.ttc ...Force constants read ...epsilon and Z* read ...Raman cross sections read Acoustic Sum Rule: || Z*(ASR) - Z*(orig)|| = 1.029894E+00 Acoustic Sum Rule: ||dyn(ASR) - dyn(orig)||= 2.701556E-01 A direction for q was not specified:TO-LO splitting will be absent Polarizability (A^3 units) multiply by 0.759092 for Clausius-Mossotti correction 262.517180 -0.000000 -0.000000 -0.000000 262.517180 -0.000000 0.000000 0.000000 57.305445 IR activities are in (D/A)^2/amu units Raman activities are in A^4/amu units multiply Raman by 0.576221 for Clausius-Mossotti correction # mode [cm-1] [THz] IR Raman depol.fact 1 -0.00 -0.0000 0.0000 16.3234 0.7500 2 -0.00 -0.0000 0.0000 3355.0146 0.7500 3 -0.00 -0.0000 0.0000 1478.4689 0.7500 4 0.00 0.0000 0.0000 285.5435 0.7500 5 0.00 0.0000 0.0000 873.4000 0.7500 6 0.00 0.0000 0.0000 1623.8289 0.7500 7 73.38 2.1998 0.0000 696.8190 0.7500 8 73.38 2.1998 0.0000 696.8152 0.7500 9 115.30 3.4567 0.2787 0.0000 0.7500 10 177.24 5.3134 1.7092 44473.2909 0.7500 11 177.24 5.3134 1.7092 44473.2914 0.7500 12 367.09 11.0050 0.0000 11288132.4685 0.1106 13 436.75 13.0934 0.2992 3721.4221 0.7500 14 436.75 13.0934 0.2992 3721.4231 0.7500 15 462.38 13.8617 0.0000 0.0004 0.7500 16 631.59 18.9347 0.0000 13677.2759 0.7500 17 631.59 18.9347 0.0000 13677.2842 0.7500 18 778.46 23.3377 0.0792 0.0000 0.7500 19 802.57 24.0605 12.9665 1800840.5786 0.7500 20 802.57 24.0605 12.9665 1800840.5109 0.7500 21 907.11 27.1945 0.0000 8355726.6168 0.1191 22 1101.10 33.0101 0.0000 0.0000 0.7500 23 1150.13 34.4801 26.2055 16251271.1703 0.7500 24 1150.13 34.4801 26.2055 16251270.4526 0.7500 25 1189.02 35.6458 0.0000 16979.5440 0.2674 26 1337.59 40.1000 27.2231 16068754.7864 0.7500 27 1337.59 40.1000 27.2231 16068754.1344 0.7500 -------------------------------------------------------------------------------------------------------- Below is my input file for pw.x &CONTROL calculation = "scf", prefix = "ttc", pseudo_dir = "/home/weilunt/pseudopotential/norm_conserving/pz", outdir = "./tmp", forc_conv_thr = 1.0D-6, etot_conv_thr = 1.0D-6, / &SYSTEM assume_isolated = 'martyna-tuckerman', ibrav = 4, A = 17.2, C = 10, nat = 9, ntyp = 3, ecutwfc = 80.D0, !better 120 tot_charge = -3, occupations = 'fixed', / &ELECTRONS conv_thr = 1.D-14, mixing_beta = 0.7, electron_maxstep = 200, / &IONS / ATOMIC_SPECIES S 32.070 S.pz-hgh.UPF N 14.007 N.pz-hgh.UPF C 12.010 C.pz-hgh.UPF ATOMIC_POSITIONS (angstrom) S 0.0000000000 -3.0749791762 -0.0000000000 S -2.6627598154 1.5374395881 -0.0000000000 S 2.6627598154 1.5374395881 0.0000000000 N 1.1913527585 -0.6879250817 -0.0000000000 N -1.1913527585 -0.6879250817 0.0000000000 N 0.0000000000 1.3757501635 0.0000000000 C 0.0000000000 -1.3240902237 -0.0000000000 C -1.1466139383 0.6620951119 0.0000000000 C 1.1466139383 0.6620951119 0.0000000000 K_POINTS (automatic) 1 1 1 0 0 0 ----------------------------------------------------------------------------------------- Thank you for your time and your help in advance, Weilun Tang _______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
