cdef extern from * nogil:
    PetscErrorCode MatCreateBSE(PetscMat,PetscMat,PetscMat*)
    PetscErrorCode MatCreateHamiltonian(PetscMat,PetscMat,PetscMat,PetscMat*)
    PetscErrorCode MatCreateLREP(PetscMat,PetscMat,PetscBool,PetscMat*)

