It is clear from section 
that the optimisation
procedure () produces a trial wavefunction, 
, that has a
VMC energy significantly closer to the DMC energy. However, there is
still room for improvement (about 0.42 eV per atom). It was therefore
decided to attempt to optimise another part of the wavefunction
() to see if the VMC energy could be reduced still further.
The most obvious candidate for further optimisation was the Jastrow
function as this also has a form in which optimisation of a set of
parameters can be performed.