Chemically accurate energy barriers of small gas molecules moving through hexagonal water rings

Abstract

We present chemically accurate potential energy curves of CH₄, CO₂ and H₂ moving through hexagonal water rings, calculated by CCSD(T)/aug-cc-pVTZ with counterpoise correction. The barriers are extracted from a potential energy surface obtained by allowing the water ring to expand while the gas molecule diffuses through. State-of-the-art XC-functionals are evaluated against the CCSD(T) potential energy surface.