Hi Giacomo and nwchem maintainer, I should provide you some important hints at this point.
> However, lapack and blas libs with 64 bit integer interfaces just appeared > on debian experimental, and have been available for some time in the > non-free (but packaged in non-free) Intel MKL libs. I forgot to mention in the changelog of src:lapack that CBLAS64 (the 64bit indexing C interface) is not yet available, while the rest are fine. Patching work was planned but currently lacks support from upstream. Currently libraries that provide CBLAS64 ABI are: libblis64-2, libmkl-rt. > export BLAS_SIZE=8 > export BLAS_LIB=-lmkl_blas95_ilp64 -Wl,--start-group -lmkl_gf_ilp64 > -lmkl_intel_thread -lmkl_core -Wl,--end-group > ... > export BLASOPT="-lmkl_blas95_ilp64 -lmkl_lapack95_ilp64 -lmkl_scalapack_ilp64 > -Wl,--start-group -lmkl_gf_ilp64 > -lmkl_intel_thread -lmkl_core > -lmkl_blacs_openmpi_ilp64 -Wl,--end-group -liomp5 -lpthread -lm -ldl" > export BLACS=$(SCALAPACK) If nwchem decides to link against MKL, it has to leave the main section. If nwchem's 64-bit indexing mode doesn't call the CBLAS64 API, you can go ahead and link the program against src:lapack's libblas64.so and liblapack64.so . The update-alternatives mechanism will allow you to switch the backend to MKL at runtime.
