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<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;">Dear Akkarach,</div>
<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;">You may play with "alpha_mix(i)", where i is the iteration number.</div>
<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;">HTH</div>
<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;"> </div>
<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;">Mahmoud</div>
<div style="font-size: 16px; font-family: Tahoma; color: rgb(0, 0, 0); font-weight: 400; font-style: normal;"> </div>
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<div style="font-family: Tahoma; color: rgb(0, 0, 0); font-size: 16px; font-weight: 400; font-style: normal;">---------------------------------------</div>
<div>Mahmoud Payami</div>
<div>NSTRI, AEOI, Tehran, Iran</div>
<div style="font-family: Tahoma; color: rgb(0, 0, 0); font-size: 16px; font-weight: 400; font-style: normal;"> </div>
<div style="font-family: Tahoma; color: rgb(0, 0, 0); font-size: 16px; font-weight: 400; font-style: normal;">Email: mpayami@aeoi.org.ir</div>
<div style="font-family: Tahoma; color: rgb(0, 0, 0); font-size: 16px; font-weight: 400; font-style: normal;">Phone: +98 (0)21 82066504</div>
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<blockquote class="as91pFk8AX8sDPOUp66RUy8IoCRjefxNG8oLk8fg" style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">From: Akkarach Sukserm via users <users@lists.quantum-espresso.org><br />
To: users@lists.quantum-espresso.org<br />
Date: Fri, 26 Nov 2021 13:55:59 +0100<br />
Subject: [QE-users] Phonons for a metal with DFT+U at finite q-points<br />
<div style="font-family: monospace, courier new, courier">Dear QE developer and users:<br />
<br />
I am trying to calculate phonons for a metal with DFT+U at finite q-points<br />
(different from Gamma) with the ph.x code. With a few exceptions (very low<br />
U), the self-consistent iteration of the phonon calculation does not<br />
converge.<br />
My system is a SrCoO3 which is a metal and ferromagnetic material. I use a<br />
DFT+U calculation for considering the magnetic atom (Co) including the<br />
smearing method for the metal system. I have tried to vary the parameters,<br />
such as U-parameter, k-point grid = 4x4x4 and 8x8x8, degauss of smearing,<br />
and pseudopotential types.<br />
A representative set of SCF and PH inputs are below.<br />
Do you have a suggestion or a method to solve this problem?<br />
Thank you in advance.<br />
<br />
Akkarach Sukserm<br />
ICTP, Italy<br />
<a href="mailto:asukserm%40ictp.it">asukserm@ictp.it</a><br />
<br />
----------------------------------------------------------------------<br />
&CONTROL<br />
calculation = "scf"<br />
forc_conv_thr = 1.00000e-04<br />
nstep = 100<br />
outdir = "./temp/"<br />
prefix = "prefix"<br />
pseudo_dir = "./PP_PAW_PBE"<br />
/<br />
&SYSTEM<br />
degauss = 1.00D-02 # vary 0.01, 0.02, 0.05, 0.08<br />
ecutrho = 7.20D+02<br />
ecutwfc = 8.00D+01<br />
ibrav = 0, nat = 5<br />
nspin = 2, ntyp = 3<br />
occupations = "smearing" , smearing = "marzari-vanderbilt"<br />
starting_magnetization(2) = 0.50D0<br />
lda_plus_u = .TRUE.<br />
hubbard_u(2) = 3.00D0 # vary U= 1.25 and 3.00 eV<br />
/<br />
<br />
&ELECTRONS<br />
conv_thr = 1.0e-08<br />
diago_david_ndim = 4<br />
diagonalization = "david"<br />
mixing_beta = 0.7D0<br />
mixing_mode = "plain", startingpot = "atomic", startingwfc =<br />
"atomic+random"<br />
/<br />
K_POINTS {automatic}<br />
8 8 8 0 0 0 # vary kp-mesh = 4x4x4 and 8x8x8<br />
<br />
CELL_PARAMETERS {bohr}<br />
7.216934286 0.000000000 0.000000000<br />
0.000000000 7.216934286 0.000000000<br />
0.000000000 0.000000000 7.216934286<br />
<br />
ATOMIC_SPECIES # vary (1) PAW-PBE, (2) PAW-PBEsol, (3) USPP-PBEsol<br />
Sr 87.62000 Sr.pbe-spn-kjpaw_psl.1.0.0.UPF<br />
Co 58.93320 Co.pbe-spn-kjpaw_psl.0.3.1.UPF<br />
O 15.99940 O.pbe-n-kjpaw_psl.1.0.0.UPF<br />
<br />
ATOMIC_POSITIONS {crystal}<br />
Sr 0.000000 0.000000 0.000000<br />
Co 0.500000 0.500000 0.500000<br />
O 0.500000 0.500000 0.000000<br />
O 0.500000 0.000000 0.500000<br />
O 0.000000 0.500000 0.000000<br />
----------------------------------------------------------------------<br />
This is my ph.x input:<br />
----------------------------------------------------------------------<br />
Phonon of SrCoO3 at q = 0, 0, 0.25 #NAME TAG<br />
&inputph<br />
tr2_ph=1.0d-12,<br />
amass(1)=87.62000,<br />
amass(2)=58.93320,<br />
amass(3)=15.99940,<br />
prefix='prefix',<br />
alpha_mix(1)=0.7D0 # Vary 0.5 and 0.7<br />
outdir='./temp/'<br />
fildyn='./ SrCoO3_q.dynq',<br />
/<br />
0.0 0.0 0.25<br />
----------------------------------------------------------------------<br />
This is my ph.x output:<br />
---------------------------------- PH.out ----------------------------<br />
Representation # 1 mode # 1<br />
<br />
Self-consistent Calculation<br />
iter # 1 total cpu time : 2300.3 secs av.it.: 17.2<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 9.086E-03<br />
<br />
iter # 2 total cpu time : 2384.5 secs av.it.: 29.1<br />
thresh= 9.532E-03 alpha_mix = 0.700 |ddv_scf|^2 = 1.768E+01<br />
<br />
iter # 3 total cpu time : 2469.9 secs av.it.: 29.9<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 1.807E+01<br />
<br />
iter # 4 total cpu time : 2533.8 secs av.it.: 20.9<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 4.797E+01<br />
<br />
iter # 5 total cpu time : 2607.1 secs av.it.: 24.9<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 1.311E+02<br />
…<br />
iter # 98 total cpu time : 21889.7 secs av.it.: 138.5<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 1.431E+49<br />
<br />
iter # 99 total cpu time : 22224.4 secs av.it.: 139.3<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 4.764E+49<br />
<br />
iter # 100 total cpu time : 22563.4 secs av.it.: 140.9<br />
thresh= 1.000E-02 alpha_mix = 0.700 |ddv_scf|^2 = 1.497E+50<br />
<br />
End of self-consistent calculation<br />
No convergence has been achieved<br />
------------------------- DONE --------------------------<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
<br />
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