Use the qmax command near the beginning of your PBS script. The qmax command takes a single argument, the maximum walltime a job should run. You can specify the walltime in seconds, minutes, or hours by adding a ‘s’, ‘m’, or ‘h’ suffix to qmax. Seconds are the default. For example, to limit a job to a maximum of 2 hours, your PBS script would look like this:
#PBS -l nodes=2:ppn=16:cobalt qmax 2h module load liggghts mpirun liggghts < in.chute_wear
Wall Time is the actual time (as shown on a wall clock) that a job runs.