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

[Paolo Giannozzi]

Segfaults with no other error message are often out-of-memory errors. 
pp.x may or may not be optimized for memory usage (some parts are not 
optimized at all, I guess, because it is not worth the effort for 
typical use cases). If there is something wrong with case nspin=2, it 
should be reproducible with much smaller runs as well.

Paolo


On 12/9/25 09:10, Konrad Gruszka via users wrote:
> 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
> 
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216