/*! \page dev_psi Trial Wave Functions

Each <c>wavefunction</c> XML element defines a trial wavefunction generally expressed as
\f[
\Psi_T({\bf R})=\Pi_k\Psi_k 
\f]
and WaveFunctionFactory processes the child nodes to add orbital components:
\code
<wavefunction name="psi0" target="e">
  <jastrow name="J1" type="OneBody" function="bspline" source="ion0"/>
  <jastrow name="J2" type="TwoBody" function="bspline" source="e"/>
  <determinantset>
  </determinantset>
</wavefunction>
\endcode
The <c>wavefunction\@target</c> associates the trial wavefunction with the quantum
particle set, "e", and their positions \f${\bf R}\f$. 
Note that there can be several <c>wavefunction</c> and the <c>name</c> and
<c>target</c> are used to distinguish them. The scoping works so that there is no need to provide target for
each orbital.

Internally, the log form of the trial wavefunction is used as
\f[
\ln \Psi_T({\bf R})=\sum_k\ln\Psi_k 
\f]
where \f$\Psi_k\f$ are derived classes from OrbitalBase.


\subpage dev_jastrow

\subpage einsplinebuilder
*/