FEAST Solver Package
- Solving Ax=ex or Ax=eBx,
A is real symmetric or complex Hermitian, B is symmetric or Hermitian positive definite.
- Two libraries: SMP version (one node), and MPI version (multi-nodes).
- Real/Complex and Single/Double precisions,
- All FEAST interfaces compatible with Fortran (77, 90) and C. All the FEAST interfaces require (any) BLAS and LAPACK packages.
- Source code and pre-compiled libraries provided for common architectures (x64).
- Reverse communication interfaces (RCI): Maximum flexibility for application-specific.
- Predefined driver interfaces for dense, banded, and sparse formats: Less flexibility but
easy to use ("plug and play")
- Large number of examples provided and documentation included,
- FEAST utility drivers for sparse systems included: users can provide directly their sparse systems for quick testing, timing, etc. .
- FEAST for non-symmetric eigenvalue problem (including non-Hermitian and complex symmetric).
- NLFEAST, new scheme for solving the non-linear eigenvector problems (e.g. for electronic structure calculations).
Some of the important capabilities of the FEAST algorithm described in 
can be outlined as follows:
- Fast convergence - FEAST converges in ~2-3 iterations with very high accuracy
- Naturally captures all multiplicities
- No-(explicit) orthogonalization procedure
- Reusable subspace - can benefit from suitable initial guess for solving series of eigenvalue problems that are close one another
- Ideally suited for large sparse systems- allows the use of iterative methods.
- the scalability of the FEAST algorithm is first and foremost dependent on the scalability of the inner
linear system solver;
- Three levels of parallelism: (i) many search interval
can be run independently (no overlap), (ii) the independent inner linear systems can be solved simultaneously on each nodes (using FEAST-MPI),
(iii) within a given node, the inner system solver can be solved in parallel (currently with shared memory capability).