The Calculation of the Electron Affinity of Atoms and Molecules

Abstract

Non-local density functional theory, as implemented in the code DMol, has been used to calculate the electron affinity of a set of 44 small atoms and molecules. A judicious choice of basis sets produces a root mean square deviation from recommended values of 0.1 eV and 0.3 eV for atoms and small molecules (with positive electron affinities) respectively. Applying DMol to calculations of temporary anion states or resonances of linear alkanes to n = 36 (where n is the number of carbon atoms) a gradual increase in electron affinity is predicted which appears to have converged by n = 36 to -0.75 eV (in agreement with experimental data for C₃₆ and polyethylene).

Key Words:

• Electron affinity
• DMol
• alkanes
• metastable states