S1 Supporting Information Theoretical Analysis of the Sequential Proton-Coupled Electron Transfer Mechanisms for H 2 Oxidation and Production Pathways Catalyzed by Nickel Molecular Electrocatalysts Laura E. Fernandez, Samantha Horvath, and Sharon Hammes-Schiffer * Department of Chemistry, 104 Chemistry Building, Pennsylvania State University, University Park, PA 16802. Table of Contents Page 1. Description of computational methods for calculation of solvent reorganization energies for (Me,Me) bb S2 2. Table S1: solvent reorganization energies for proton transfer S4 3. Table S2: solvent reorganization energies for electrochemical electron transfer S5 4. Structural and energetic information for all studied systems: Tables S3 – S34 S6 – S83 * Corresponding author: shs@chem.psu.edu.