As a consequence, this particle can only exist in a certain number of
eigenstates that correspond to the energy eigenvalues
$\varepsilon_\ell$ admitted as solutions of this equation. The
-Copenhagen interpretation of quantum mechanics posits that, if a
+orthodox interpretation of quantum mechanics posits that, if a
particle has energy $\varepsilon_\ell$ then the probability of finding
it at location $\mathbf x$ is proportional to $|\Psi_\ell(\mathbf
x)|^2$ where $\Psi_\ell$ is the eigenfunction that corresponds to this
that case, we may want to start solving a vector-valued problem
instead.
+<li> Our implementation of the deal.II library here uses the
+PETScWrappers and SLEPcWrappers and is suitable for running on serial
+machine architecture. However, for larger grids and with a larger
+number of degrees-of-freedom, we may want to run our application on
+parallel architectures. A parallel implementation of the above code
+can be particuarily useful here since the generalized eigenspectrum
+problem is somewhat more expensive to solve than the standard problems
+considered in the tutorial up-to-now. Fortunately, modifying the above
+program to be MPI complient is a relatively straightforward
+procedure. A sketch of how this can be done can be found in @ref
+step_17 "step-17".
+
</ul>