Check XC_FLAGS_NEEDS_LAPLACIAN before trying to use a MGGA
Example: XC_MGGA_X_BR89 needs the laplacian of the density, which GPAW doesn't support.
See also: https://listserv.fysik.dtu.dk/pipermail/gpaw-users/2019-November/005845.html
Edited by Jens Jørgen Mortensen