How do I restore files accidentally deleted by the move operation in finder?
STOP ALL FILE OPERATIONS AND UNMOUNT YOUR HARD DRIVE

If you haven't written to the Drive since then, it will eventually save you.

When Moving files like this, they get marked as deleted on the drive.
Therefore you can only try to recover them.

Which means: 


Get a Recovery-Software like DataRescue
Or a free (CLI) programm like PhotoRec
Try recovering the files.