POSITRON SCATTERING BY He, Mg, Ca AND Zn C.P.Campbell+, Jennifer Blackwood+, Mary T.McAlinden++ and H.R.J.Walters+ +Department of Applied Mathematics, Queen's University, Belfast BT7 1NN, UK. ++ School of Computing, Staffordshire University, Beaconside, Stafford ST18 0DG, UK. Positron scattering by He, Mg, Ca and Zn is treated in the coupled - pseudostate formalism using up to 36 atomic states and positronium eigenstates up to Ps(n=3). Results will be presented for positronium formation, ionization, discrete excitation of the atom and total scattering.