How to obtain accurate results with molecular iodine and density functional theory?

Abstract

AbstractMolecular iodine is found in many organic synthetic methodologies, both as reagent and as catalyst. Naturally, many groups have carried out computational studies involving this element. However, the choice of computational method proves to be more challenging than for other non‐metals. We quantify herein the errors that some common theory levels can introduce in terms of both structural and energetic deviations. We also evaluate multiple post hoc corrections, namely, vibrational entropy, dispersion, and counter‐poise corrections. Our results indicate the triple‐ basis sets are essential to obtain quality results and that post hoc corrections are overall detrimental.