I am performing relax calculation using DFT, on Quantum espresso. I have accidentally deleted the out directory (temp folder). My calculations are still running without that folder. Are those calculations considered as valid?
The fact that the calculation didn't stop suggests that the deleted files weren't immediately needed for the current step. However, you may have deleted important files that QE relies on for later steps, or files you were expecting to have from this run. I regret to say it’s best to stop the calculation and start over.
I would let the calculation finish. The outcome depends also on the disk_io flag. With disk_io low you might be able to continue the calculations as QE will write files only at the end of it. Check also if the energy/forces smoothly change between different relaxation steps. Finally, you might let the calculation finish, then use the final structure as input and check if the forces are really small.