``GMX_NOOPTIMIZEDKERNELS``
deprecated, use ``GMX_DISABLE_SIMD_KERNELS`` instead.
-``GMX_NO_ALLVSALL``
- disables optimized all-vs-all kernels.
-
``GMX_NO_CART_REORDER``
used in initializing domain decomposition communicators. Rank reordering
is default, but can be switched off with this environment variable.