Was the calculation submitted within a job? On MSI systems all significant calculations must be submitted as jobs using a job script. Calculations run outside of jobs are only allowed to continue for a short amount of time. Jobs are the mechanism by which the clusters are shared between many users. Each job waits in the job queue until the job scheduler can find appropriate open nodes for the calculation.
The way to create and submit job scripts is described on the Job Submission and Scheduling webpage.
A list of job queues available on the different MSI systems is available on the Queues webpage.
Calculations may also be killed if they use more resources than requested within the job script. We recommend that you check that calculation memory and core usage agree with the job resource request.