mpich-doc binary package in Ubuntu Oracular arm64

 MPICH is a high-performance and widely portable implementation of the
 MPI-4.1 standard from the Argonne National Laboratory.
 It efficiently supports different computation and communication platforms
 including commodity clusters, SMPs, massively parallel systems, and
 high-speed networks.
 This release has all MPI 4.1 functions and features required by the standard
 with the exception of support for the "external32" portable I/O format and
 user-defined data representations for I/O.
 .
 This package includes the MPICH documentation.

Source package