libblacs-openmpi1 binary package in Ubuntu Bionic arm64

 The BLACS project is an ongoing investigation whose purpose is to
 create a linear algebra oriented message passing interface that may be
 implemented efficiently and uniformly across a large range of
 distributed memory platforms.
 .
 You can choose between an implementation based on MPI or PVM. This package
 uses MPI. There are packages for the shared libraries (this one), for the
 static libraries and the development files, and for test programs.
 .
 Most users do not need to install this package directly because it is
 used as a high level driver for the communication in the ScaLAPACK packages.
 Therefore, it is installed when installing ScaLAPACK. ScaLAPACK is a
 parallel version of LAPACK and is used on Beowulf type clusters.

Source package