Electron Collisions with Formic Acid and Tetrahydrofuran

We have measured absolute elastic electron scattering cross sections for the biologically relevant molecules CHOOH (formic acid) and C$_4$H$_8$O (tetrahydrofuran - THF). The formate group is an important constituent of a number of amino acids and THF forms part of the DNA backbone. The experiments cover the energy range from 1 to 50 eV and include both angular and energy dependent measurements. We make comparisons with a number of theoretical approaches, including the Kohn variational, and R- matrix techniques and a calculation based on a density functional technique.