I don't think that the electron-phonon calculation has been ported to GPUs
Paolo
On 11/25/25 06:52, Dolon Pal via users wrote:
Dear Quantum ESPRESSO Developers and Community,
I am writing to report a persistent runtime error in the GPU-accelerated
version of |ph.x| (Quantum ESPRESSO v7.5) when calculating electron-
phonon coefficients using the OpenACC port.
While the code successfully calculates the Dynamical Matrices and
Frequencies on the GPU, it consistently crashes during the final
electron-phonon interaction step (routine |elphon|) with a File I/O
error, specifically related to the temporary file |a2Fsave|.
*1. System and Compilation Details:*
*
*Version:* Quantum ESPRESSO v7.5 (GitLab release)
*
*Compiler:* NVIDIA HPC SDK v24.9
*
*Configuration:* |./configure --enable-openacc --with-cuda=yes --
with-cuda-cc=89 --with-cuda-runtime=12.6|
*
*Hardware:* NVIDIA RTX 4090 (Ada Lovelace)
*
*MPI:* OpenMPI (via NVIDIA HPC SDK)
*2. The Issue:* When running |ph.x| with |electron_phonon =
'interpolated'| (or any mode that triggers |elphon|), the execution
aborts immediately after diagonalizing the dynamical matrix for the
first q-point. The crash occurs regardless of the MPI parallelization
level (reproduced with both |-np 1| and |-np 8|).
*3. Error Log:* The crash points to a read error in |elphon.f90|
attempting to read a file that appears to be empty or not flushed to disk.
|FIO-F-217/list-directed read/unit=40/attempt to read past end of
file. File name = './out/mgb2.a2Fsave', formatted, sequential access
record = 1 In source file /path/to/q-e/PHonon/PH/elphon.f90, at line
number 847 |
|File name = './out/mgb2.a2Fsave', formatted, sequential access record =
1 In source file /path/to/q-e/PHonon/PH/elphon.f90, at line number 847 |
*4. Reproduction Case (MgB2):* I reproduced this using a standard MgB2
test case.
/Input snippet (|ph.in|):/
Fortran
|&INPUTPH tr2_ph = 1.0d-14, prefix = 'mgb2', outdir = './out', fildyn =
'mgb2.dyn', fildvscf = 'mgb2.dvscf', electron_phonon = 'interpolated', !
<--- Triggers the crash trans = .true., ldisp = .true., nq1=6, nq2=6,
nq3=4 / |
*5. Observations:*
1.
*Pure Phonons work:* If I comment out |electron_phonon|, the GPU run
finishes successfully and writes |.dyn| and |.dvscf|files.
2.
*CPU Works:* The exact same input runs successfully on the CPU-only
binary (gfortran compilation).
3.
*File Incompatibility:* I attempted to run the heavy phonon
calculation on the GPU and the final electron-phonon collection on
the CPU (using |recover=.true.| or |trans=.false.|), but the CPU
binary cannot read the GPU-generated |.dvscf|/binary files
("problems reading u" error), likely due to binary format/padding
differences between |nvfortran|and |gfortran|.
It appears there is a race condition or file handling issue in the
OpenACC implementation of the |elphon| routine where the |a2Fsave| file
is read before it is successfully written/closed.
Any advice on a workaround or a patch for |elphon.f90| to stabilize the
GPU I/O would be greatly appreciated.
Thank you for your time and for developing this software.
Best regards,
Dholon Kumar Paul
Research Assistant, BRAC University, Bangladesh
_______________________________________________________________________________
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]
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--
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216
_______________________________________________________________________________
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
