I'd like to run some semi-large CI expansions, where I need to compile dalton with 64 bit ints (more than 2^32 - 1 configurations). Also, I'd like to use MPI for inter-node parallelism. I can compile with 64 bit ints without problems when not using MPI. I have tried two setups, both giving too many errors. a) Dalton 2018.2, Intel 2019, mpich and mkl `$ ./setup --int64 --fc=mpifort --cc=mpicc --cxx=mpicxx` b) Dalton 2018.2, GCC 9.2, mpich and lapack-i8 `$ ./setup --int64 --fc=mpif90 --cc=mpicc --cxx=mpicxx` Attached are the output from `make`. Approach a) gives a bunch of warnings related to the C files in the DFT modules, which are essentially the same as the one I got when compiling without MPI. However, I also get errors related to the lucita parallelization stuff. Approach b) gives errors related to parallel routines from abacus it would seem. [log_gcc](/uploads/6922c211cc6fe4b3987faa41c5f9f25a/log_gcc) [log_intel](/uploads/39e4d9b40b34546c5dd3056cbcb79453/log_intel) Any help is appreciated. Also, thanks for maintaining dalton :smile: