How to correctly determine the `-march` flag when working with Intel oneAPI on Intel processors?

The simplest thing, I think, is to not use -xHost when running the VASP validation test. You shouldn’t be using -xHost in an MPI environment anyway, unless all your nodes have the same processor.

If the VASP validation test is looking for an exact FP value, that’s its error. If it accepts a small variation, perhaps the range needs to be widened a bit to accommodate more advanced vectorizations.