# Invalid INCAR fixture for vasp.parallel.kpar_incompatible
# KPAR (https://www.vasp.at/wiki/index.php/KPAR) parallelizes over
# k-points, while NCORE (https://www.vasp.at/wiki/index.php/NCORE)
# parallelizes over bands/orbitals. The two operate on different MPI
# partitioning axes: KPAR splits the MPI ranks into k-point groups, and
# NCORE then governs how the remaining ranks within each group share a
# single orbital. Declaring both KPAR > 1 and NCORE > 1 without an
# externally-supplied total MPI rank count leaves the combined layout
# undefined and is the canonical incompatible parallelization
# combination documented on the VASP wiki. This must surface
# vasp.parallel.kpar_incompatible at warning severity, underlining the
# NCORE line (the band-parallelism flag the user should reconcile with
# the k-point parallelization).
KPAR = 4
NCORE = 4
