Always specify %NProcShared and %Mem .
To run a Gaussian job, you use the g16 command followed by the input file ( .com or .gjf ) and an output file ( .log or .out ): g16 < input.com > output.log & Use code with caution. Understanding the Input File A standard G16 input includes:
# Gaussian 16 Environment Variables export g16root=/opt export GAUSS_SCRDIR=/scratch/$USER mkdir -p $GAUSS_SCRDIR # Initialize Gaussian settings source $g16root/g16/bsd/g16.profile Use code with caution. Key Variables Explained: gaussian 16 linux
💡 : Use the g16.profile or g16.login scripts provided in the installation directory to automatically set up your environment variables ( $g16root , $GAUSS_SCRDIR ) upon login. Gaussian 16 Features at a Glance
| Component | Recommended Specification | Notes | | :--- | :--- | :--- | | | ~2-3 GB (executables) + 200 GB+ (scratch) | The program files require 2-3 GB. For large jobs, especially post-SCF calculations like MP2 or CCSD, temporary scratch space of up to 200 GB or more is essential. | | Memory (RAM) | 256 GB or higher | While the default memory allocation in Gaussian is 800 MB, computational nodes for production runs often feature 256 GB or more to handle large systems. | | Swap Space | 1-2 GB | This is in addition to physical RAM. | | CPU | Modern x86_64 with AVX2 support | For optimal performance, CPUs that support the AVX2 instruction set (e.g., Intel Haswell or newer) are highly recommended. | Always specify %NProcShared and %Mem
#!/bin/bash #SBATCH --job-name=G16_Opt #SBATCH --output=res_%j.log #SBATCH --error=err_%j.log #SBATCH --nodes=1 #SBATCH --ntasks-per-node=1 #SBATCH --cpus-per-task=16 #SBATCH --mem=48G #SBATCH --time=24:00:00 #SBATCH --partition=compute # Load environment if not inherited export g16root=/usr/local . $g16root/g16/bsd/g16.profile export GAUSS_SCRDIR=/scratch/$SLURM_JOB_ID mkdir -p $GAUSS_SCRDIR # Execute Gaussian 16 g16 < molecule.gjf > molecule.log # Clean up scratch space after clean exit rm -rf $GAUSS_SCRDIR Use code with caution. Submit this job file to the cluster queue using: sbatch submit_g16.sh Use code with caution. Troubleshooting Common Linux Errors Error Message / Symptom Root Cause Erroneous write. nwritten=-1 The scratch disk is completely full.
Pro tip: Do not mix GPU and Linda parallelization without careful benchmarking. Overhead often kills performance. Key Variables Explained: 💡 : Use the g16
Gaussian 16 is a powerful electronic structure modeling program for predicting the energies, molecular structures, vibrational frequencies, and chemical properties of molecules and reactions. While it is widely used in academic and industrial research, its effective operation on Linux—the most common platform for computational chemistry—requires careful attention to the operating system environment. This guide aims to provide a structured walkthrough of the entire process, from installation to performance tuning on a Linux cluster.
: Features dynamic task allocation and an optimized memory algorithm that reduces disk I/O during complex CCSD iterations.
