  The time-dependent Hartree-Fock approach may be derived from a variational
principle and a Slater Determinant wavefunction Ansatz. It gives a good
description of nuclear processes in which one-body collisions dominate and has
been applied with success to giant resonances and collisions around the
barrier. It is inherently unable to give a good description of two-body
observables. A variational principle, due to Balian and Veneroni has been
proposed which can be geared to good reproduction of two-body observables.
Keeping the Slater Determinant Ansatz, and restricting the two-body observables
to be the squares of one-body observables, the procedure can be implemented as
a modification of the time-dependent Hartree-Fock procedure. Applications,
using the Skyrme effective interaction, are presented for the mass
distributions of fragments following de-excitation of the giant dipole
resonance in S-32. An illustration of the method's use in collisions is given.
