eigenfunctions unitary[@Pezz8301], $$\Lambda=\Lambda_{\svec{P}}=
\sqrt{m \over{(2\pi)^3 E}}\  {\cal L}, \eqno(3.6)$$ where the term ${\cal L}$ is the Lorentz Boost operator of eq. (2.5b). Using the property of the Lorentz operator, ${\bf p}{\cal L} = {\cal L} m \basis{4}$ from eq. (2.5a), the unimodular meta-monogenic multivector eigenfunction can be expressed in the alternate form, $$\eigen{\Psi} (x) =
\Lambda_{\svec{P}}\ \exp{(-\basis{4}\ p_{\mu}x^{\mu})}, \eqno(3.7a)$$ $$=(\Box + m)\ \eigen{\Phi}(x), \eqno(3.7b)$$ $$\eigen{\Phi} (x)=
{\exp{(-\basis{4}\ p_{\mu}x^{\mu})}\over
(2\pi)^{3 \over 2} \sqrt{2E(E+m)}}. \eqno(3.7c)$$

Now we see that each eigenfunction has the [*same*]{} generator of quantum phase, the (positive parity) unit time vector $\basis{4}$ when multiplied [*dextrally*]{} (right-side applied). Further the meta-monogenic eigenfunction $\eigen{\Psi}({\bf x})$ can be written in terms of a multivector solution $\eigen{\Phi} ({\bf x})$ to the Klein-Gordon equation, again complex $\basis{4}$. This differs from the work of Hestenes[@Hestenes82] and Benn[@Benn] which both interpret the negative parity geometric pseudoscalar as playing the role of $i$. Eigenfunctions in that form will not obey the standard parity relation, which ours do, $${\cal P}\left( \eigen{\Psi} (\tpo{X}{t}) \right) =
-\basis{4}\ \eigen{\Psi} (\tpo{X}{t})\ \basis{4} =
+ {{\Psi}_{-\svec{P}}} (\tpo{-X}{t}). \eqno(3.8)$$

The unitary meta-mongenic eigenfunctions are orthonormal and complete, $$\int d^3{\vec{\bf X}}\ \Psi_{\svec{K}}^{\dagger}(\tpo{X}{t})
\ \eigen{\Psi}(\tpo{X}{t}) = \delta_{\svec{K}, \svec{P}}, \eqno(3.9a)$$ $$\delta(\vector{X}-\vector{Y}) = \int d^3\vector{P}\ \eigen{\Psi}(\tpo{X}{t})
\ \eigen{\Psi}^{\dagger}(\tpo{Y}{t}).  