I have been trying to run a calculation on the cluster using Orca 4.0 but for some reason I have been receiving an error message saying: 'Cannot open file Filename: xx.grad.tmp". It looked through the files created by running the script file on the cluster to see if I could find any file with the grad.tmp format but I could not. However, I tried running this calculation using my PC to see if I would get similar error message but as you know, it will take longer time. But, I was able to find a file in the grad.tmp format when I tried running the calculation on my PC. This makes me feel like the file is not created while running the calculation on the HPC cluster and the program is trying to access this file to be used in calculation but it could not find it which made the calculation end with a fail message. has anyone ever been in this kind of situation before and how did you went about solving the problem. I have a screenshot of the .output file attached. Thank you!