libparpack2-dev 3.7.0-3 (arm64 binary) in ubuntu focal

 ARPACK software is capable of solving large scale symmetric,
 nonsymmetric, and generalized eigenproblems from significant
 application areas. The software is designed to compute a few (k)
 eigenvalues with user specified features such as those of largest
 real part or largest magnitude. Storage requirements are on the order
 of n*k locations. No auxiliary storage is required. A set of Schur
 basis vectors for the desired k-dimensional eigen-space is computed
 which is numerically orthogonal to working precision. Numerically
 accurate eigenvectors are available on request.
 .
 This package contains the static libraries and the documentation for
 development with libparpack (including examples).