**Method:**

- very large sparse matrices from finite element computations
- condensation:
- find most important degrees of freedom(``masters'')
- reduce problem to masters, capturing main aspects of slaves

- involved hierarchical data structures
- reduction of linear dimension typically by a factor of
- condensed problem is dense

**Parallelisation:**

- master/slave program for the condensation of partial structures
- uses BLACS and basic MPI for communication
- Scalapack for the condensed generalized eigenvalue problem