A symmetry analysis based upon the structure of simple molecules and their anticipated intermolecular interactions can lead to successful predictions of molecular packing and crystal symmetry, As a demonstration of these ideas an in-depth study of the oxalamide functionality as a persistent hydrogen bonding unit is presented. The synthesis and structural characterization of a series oxalamide dicarboxylic acids is presented and the structures compared with the analogous urea compounds. Both the urea and oxalamide dicarboxylic acids form designed two-dimensional hydrogen-bonded beta-networks with a significant degree of reliability, The urea designs are quite reliable when there is a molecular 2-fold axis, but competing hydrogen bond patterns are found when less symmetrical molecules are studied. The oxalamide design based on inversion centers is also quite reliable, with the designed layer structure found in most cases.