Hello LAMMPS users,
I am encountering an error when attempting to use the MEAM potential with other potential functions using the Kokkos package for GPU acceleration.
I am using the pair_style hybrid command to use MEAM with other potentials, specifically Tersoff and Lennard-Jones (L-J).
System Information
- LAMMPS Version: lammps-22Jul2025-update-2
- Kokkos Version: 4.6.2
- Operating System: WSL-Ubuntu 24.04.1
- GPU: NVIDIA GeForce RTX 5070
- CPU: AMD Ryzen Threadripper PRO 7995WX
The Problem
The main issue appears to be that the “error :cuda illegal memory access” or “blows up” specifically when using the MEAM potential with other potentials accelerated with Kokkos-GPU. However MEAM potential alone runs perfectly fine and also runs successfully when using the CPU (without Kokkos).
I have performed several tests to isolate the problem.
The followings are the cases I have tried
Case 1
Potential function : pair_style hybrid meam meam lj/cut lj/cut
Acceleration : Kokkos - GPU
Result : Failed (Throws an cuda illegal memory access error immediately after as the input script is read)
Case 2
Potential function : pair_style hybrid meam meam lj/cut lj/cut
Acceleration : CPU (no Kokkos)
Result : Success
Case 3
Potential function : pair_style hybrid meam tersoff lj/cut lj/cut
Acceleration : Kokkos - GPU
Result : Failed (System blows up when two different object, one using a meam and the other tersoff potential, gets close)
Case 4
Potential function : pair_style hybrid meam tersoff lj/cut lj/cut
Acceleration : CPU (no Kokkos)
Result : Success
Case 5
Potential function : pair_style hybrid tersoff tersoff lj/cut lj/cut
Acceleration : Kokkos - GPU
Result : Success
Case 6
Potential function : pair_style hybrid tersoff tersoff lj/cut lj/cut
Acceleration : CPU (no Kokkos)
Result : Success
Case 7
Potential function :pair_style meam
Acceleration : Kokkos - GPU
Result : Success
Commands Used
Kokkos - GPU Run Command:
mpirun -np 1 lmp -k on g 1 -sf kk -pk kokkos neigh half newton on -in test.lmp
CPU Run Command (for comparison):
lmp -pk omp 190 -sf omp -in test.lmp
I have uploaded the relevant input scripts, log files, dump files, and potential files for each case.
Any advice or insights into why the MEAM potential fails specifically with Kokkos-GPU acceleration would be greatly appreciated.
Thank you for your time and help.