  The confined variational method is used to generate a basis of correlated
gaussians to describe the interaction region wave function for positron
scattering from the H$_2$ molecule. The scattering length was $\approx -2.7$
$a_0$ while the zero energy $Z_{\rm eff}$ of 15.7 is compatible with
experimental values. The variation of the scattering length and $Z_{\rm eff}$
with inter-nuclear distance was surprisingly rapid due to virtual state
formation at $R \approx 3.4$ $a_0$.
