Update run_artemis.rst

Docs/source/usage/run_artemis.rst

@@ -111,6 +111,34 @@ Advanced Usage
 - **Micromagnetics**: When ``USE_LLG=TRUE``, additional array fields for magnetization components will be allocated, and the FDTD step will couple to LLG updates. 
 - **Superconductivity**: Some versions of ARTEMIS allow modeling superconductors with a two-fluid model. Ensure your input file is set up properly, referencing the parameters introduced in the relevant publication or example.
 
+Common Pitfalls
+---------------
+
+1. **MPI Rank Mismatch / Library Errors**:
+   - Ensure that your environment is loading the correct MPI library before running, e.g.:
+     ::
+       module load openmpi
+       mpirun -n 4 ./main3d...
+   - Mixing different MPI implementations at compile/run time can cause errors.
+
+2. **CUDA or HIP Errors**:
+   - If you compiled with ``USE_GPU=TRUE``, verify that your CUDA or HIP drivers match the version you used during compilation. 
+   - On HPC systems:
+     ::
+       module load cuda
+       nvidia-smi
+     to confirm GPU visibility.
+
+3. **Out-of-Memory**:
+   - Very fine meshes or many levels of AMR can exceed GPU or CPU memory. Try reducing resolution or domain size.
+   - Check if your domain decomposition is balanced across MPI ranks.
+
+4. **Missing Output Files**:
+   - Check that the parameter ``plot_int`` in your input file is set appropriately (e.g., 100 steps) to generate plotfiles.
+   - If no plotfiles are produced, you might be running fewer steps than ``plot_int``.
+
+For further assistance, please open an issue on our GitHub or consult the AMReX documentation.
+
 Further Documentation
 ---------------------