[QE-users] pp.x segfaults for occuapations='fixed' and nspin=2 calculation

[Konrad Gruszka]

Dear QE users,

I'm having a problem with pp.x calculation for semiconductor with a gap 
(occuapations='fixed') with magnetism (nspin=2 + tot_magnetization=1). 
I've tested this using QE version 7.3.1 and 7.5.

The pp.x is constantly giving me segfaults regardless of whether I want 
to do plotnum=0 or plotnum=6, while if there's no nspin=2, pp.x for 
nonmagnetic calculation goes fine. I've also tried projwfc.x to see 
magnetic moments, no luck also - segfaults.  The calculations are done 
on HPC using 192 cpu cores, I also tried on 1 CPU for pp.x:

mpirun -np 192  pw.x -npool 4 -ntg 8 -in ga.scf.in > ga.scf.out

mpirun -np 192 pp.x -in pp.in > pp.out


output from pp.x:

      Program POST-PROC v.7.5 starts on  8Dec2025 at 23: 2:54

      This program is part of the open-source Quantum ESPRESSO suite
      for quantum simulation of materials; please cite
          "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
          "P. Giannozzi et al., J. Phys.:Condens. Matter 29 465901 (2017);
          "P. Giannozzi et al., J. Chem. Phys. 152 154105 (2020);
           URL http://www.quantum-espresso.org",
      in publications or presentations arising from this work. More 
details at
      http://www.quantum-espresso.org/quote

      Parallel version (MPI & OpenMP), running on     192 processor cores
      Number of MPI processes:               192
      Threads/MPI process:                     1

      MPI processes distributed on     1 nodes
      R & G space division:  proc/nbgrp/npool/nimage =     192
      341092 MiB available memory on the printing compute node when the 
environment starts

      Reading xml data from directory:

      ./tmp/geas2_mag.save/
      file Ge.pbe-dn-kjpaw_psl.1.0.0.UPF: wavefunction(s)  4S 4P 3D 
renormalized
      file Ge.pbe-dn-kjpaw_psl.1.0.0.UPF: wavefunction(s)  4S 4P 3D 
renormalized

      IMPORTANT: XC functional enforced from input :
      Exchange-correlation= PBE
                            (   1   4   3   4   0   0   0)
      Any further DFT definition will be discarded
      Please, verify this is what you really want

After this segfault (matter of seconds after running), no additional 
info here.

Is there any known problem with such combination of system parameters or 
are my inputs just wrong?


Below is my pp.x input file:

&INPUTPP
filplot = 'ppout.rho'
outdir = './tmp'
plot_num = 0
prefix = 'geas2_mag'
/
&PLOT
fileout = 'rho.cube'
iflag = 3
output_format = 6
/

Previous to SCF I've done vc-relax, both converging fine. System is 2D 
with a vacancy that induces magnetism.

Input for SCF calculation after which I try pp.x:

&CONTROL
    calculation = 'scf'
    prefix = 'geas2_mag'
    pseudo_dir = '../pp/'
    outdir = './tmp'
    restart_mode = 'from_scratch'
    etot_conv_thr = 1.0D-5
    forc_conv_thr = 1.0D-4
    tprnfor = .false.
    tstress = .false.
/

&SYSTEM
    ibrav = 0
    nat = 71
    ntyp = 3
    ecutwfc = 80
    ecutrho = 640
    occupations = 'fixed'
    nspin=2
    tot_magnetization=1
    assume_isolated = '2D'
    starting_magnetization(1) = 0.00   ! Ge
    starting_magnetization(2) = 0.20   ! GeMAG
    starting_magnetization(3) = 0.00   ! As

/

&ELECTRONS
    conv_thr = 1.0D-10
    mixing_beta = 0.7d0
    electron_maxstep= 500
    mixing_mode = 'plain'
/

ATOMIC_SPECIES
Ge 72.64 Ge.pbe-dn-kjpaw_psl.1.0.0.UPF
GeMAG 72.64 Ge.pbe-dn-kjpaw_psl.1.0.0.UPF
As 74.9216 As.pbe-n-kjpaw_psl.1.0.0.UPF

CELL_PARAMETERS (angstrom)
   11.132390620  10.714510184   0.000000000
  -11.132390620  10.714510184   0.000000000
    0.000000000   0.000000000  30.272253940

ATOMIC_POSITIONS (angstrom)
Ge               0.0163362844        6.1146929139  16.6554928040
Ge              -0.0551119261        0.7975784520  13.5266388254
GeMAG      1.8553984371        8.6000205492       14.8011166052
Ge               1.8553984371        3.0714979901  15.4473783907
As               0.0755034661        6.9191645903  14.3261240522
As              -0.0239102020        1.5214443595  15.8854390605
As              -0.0143271795        8.0302432723  18.2433445958
...

...

As              -1.4991101973       10.1257107631  12.9365799592
As              -1.8809867461        4.6872226564  17.3505252161

K_POINTS automatic
4 4 1 0 0 0

I've truncated input file due to its size, but I could send full if needed.

Regards

Konrad Gruszka