A hybrid MP2/planewave-DFT scheme for large chemical systems: proton jumps in zeolites

Abstract

We present an embedding scheme to introduce local corrections at post Hartree–Fock level to density functional theory (DFT) calculations. As a first application we study proton jump reactions in the zeolite HSSZ-13 and show that energy barriers and rate constants are significantly changed by second-order Møller–Plesset perturbation theory (MP2) corrections to plane wave based DFT calculations. Electronic energy barriers increase from 68 to 81 kJ/mol (dry zeolite), and from 22 to 30 kJ/mol (hydrated zeolite). The predicted heats of adsorption of one water molecule onto the Brønsted acidic sites O 1 and O 2 are 73 and 69 kJ/mol, respectively.