It is still a PC, it may as part of its computation solve an eigenvalue problem but its use is as a PC, hence does not belong in SLEPc.
Barry > On Jun 26, 2019, at 1:22 PM, Jed Brown <j...@jedbrown.org> wrote: > > "Smith, Barry F." <bsm...@mcs.anl.gov> writes: > >>> You can implement and register a PC in SLEPc (it would go in libslepc.so). >> >> It makes no sense to have a PC in SLEPc. > > We're talking about a PC that is implemented by iteratively solving an > eigenproblem.