**Summary** Segmentation fault encountered during energy minimization. GROMACS was built locally and passes all tests. **GROMACS version** ``` :-) GROMACS - gmx, 2023.2 (-: Executable: /usr/local/gromacs/bin/gmx Data prefix: /usr/local/gromacs Working dir: /home/gusten/Documents/cnfbuilder/MDConf/mdp/simulations/NA-CL-0.01/tempo-L8 Command line: gmx -quiet --version GROMACS version: 2023.2 Precision: mixed Memory model: 64 bit MPI library: thread_mpi OpenMP support: enabled (GMX_OPENMP_MAX_THREADS = 128) GPU support: disabled SIMD instructions: AVX2_256 CPU FFT library: fftw-3.3.8-sse2-avx-avx2-avx2_128 GPU FFT library: none Multi-GPU FFT: none RDTSCP usage: enabled TNG support: enabled Hwloc support: disabled Tracing support: disabled C compiler: /usr/bin/cc GNU 13.2.1 C compiler flags: -fexcess-precision=fast -funroll-all-loops -mavx2 -mfma -Wno-missing-field-initializers -O3 -DNDEBUG C++ compiler: /usr/bin/c++ GNU 13.2.1 C++ compiler flags: -fexcess-precision=fast -funroll-all-loops -mavx2 -mfma -Wno-missing-field-initializers -Wno-cast-function-type-strict SHELL:-fopenmp -O3 -DNDEBUG BLAS library: External - detected on the system LAPACK library: External - detected on the system ``` **Steps to reproduce** Running the attached tpr file [em0.tpr](/uploads/247f50b84128301c10211d86c7702709/em0.tpr) with `gmx mdrun -s em0.tpr` results in a segmentation fault. The tpr was generated with `gmx grompp -f em0.mdp -c neu.gro -o em0.tpr -n groups.ndx -maxwarn 1`, using the files [neu.gro](/uploads/325314b99097f321b3e70fd7e4fadbcd/neu.gro) [topol.top](/uploads/918c9e76d6a672888a09b97c40a20e7c/topol.top) [moleculeTypes.itp](/uploads/7c8123469c4236c7a03b9b4d4623b55f/moleculeTypes.itp) [groups.ndx](/uploads/0c1241f32c4a9aaef3a7c5a4abc7bfd3/groups.ndx) [em0.mdp](/uploads/fda1dc98e9d5991d23948d8e7dfecfff/em0.mdp) and [spceAT.itp](/uploads/db748b80d7c50c73c8626070ea9d0923/spceAT.itp) [spce.itp](/uploads/2cf01662072a500a3eb30e635a973728/spce.itp) [ionsAT.itp](/uploads/def549a7a50b50ce4094dd96c00a66e7/ionsAT.itp) [ions.itp](/uploads/4d482137533a2524d204da8647a684e5/ions.itp) [glycamAT.itp](/uploads/0d51fd65cbf4562b4a7aeef2079a0959/glycamAT.itp) [glycam.itp](/uploads/a29ea9f626efc30df667688dc3d5c8cc/glycam.itp) [ff.itp](/uploads/f338d03f304d71e7087be9e75e45c91d/ff.itp) in `../../../forcefield`. **What is the current bug behavior?** On my machine I get the output: ``` :-) GROMACS - gmx mdrun, 2023.2 (-: Executable: /usr/local/gromacs/bin/gmx Data prefix: /usr/local/gromacs Working dir: /home/gusten/Documents/cnfbuilder/MDConf/mdp/simulations/NA-CL-0.01/tempo-L8 Command line: gmx mdrun -s em0.tpr Reading file em1.tpr, VERSION 2023.2 (single precision) Update groups can not be used for this system because there are three or more consecutively coupled constraints NOTE: Periodic molecules are present in this system. Because of this, the domain decomposition algorithm cannot easily determine the minimum cell size that it requires for treating bonded interactions. Instead, domain decomposition will assume that half the non-bonded cut-off will be a suitable lower bound. Using 80 MPI threads Using 1 OpenMP thread per tMPI thread There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology There were 2 inconsistent shifts. Check your topology Steepest Descents: Tolerance (Fmax) = 1.00000e+01 Number of steps = 10000 Segmentation fault (core dumped) ``` **What did you expect the correct behavior to be?** Not sure about the inconsistent shifts, but I certainly would not expect a segmentation fault. Sadly I don't have any idea of what could be causing it.