>SLEPc is the eigensolver package build on PETSc. >http://www.grycap.upv.es/slepc/ >It is easy to install and use after installing PETSc. So the Petsc can not solve it on its own w/o Slepc? >Cygwin is required to build PETSc, but not to use it. How about the MSys interface, which I've already installed. REgards,