1 Supporting Information file Reversible Complexation of Ammonia by Breaking a Manganese-Manganese Bond in a Manganese Carbonyl Ethylenedithiolate Complex: A Theoretical Study of an Unusual Type of Lewis Acid Luana-Flavia Radu, 1 Amr A. A. Attia, 1 Radu Silaghi-Dumitrescu 1 , Alexandru Lupan, 1 * and R. Bruce King* 2 1 Faculty of Chemistry and Chemical Engineering, Babe¸ s-Bolyai University, Cluj-Napoca, Romania 2 Department of Chemistry, University of Georgia, Athens, Georgia, 30602 Table S1. Initial H 2 C 2 S 2 Mn 2 (CO) n structures. Table S2A. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 4 structures. Table S2B. Energy ranking for H 2 C 2 S 2 Mn 2 (CO) 4 structures. Table S3A. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 5 structures. Table S3B. Energy ranking for H 2 C 2 S 2 Mn 2 (CO) 5 structures. Table S4A. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 6 structures. Table S4B. Energy ranking for H 2 C 2 S 2 Mn 2 (CO) 6 structures. Table S5A. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 7 structures. Table S5B. Energy ranking for H 2 C 2 S 2 Mn 2 (CO) 7 structures. Table S6A. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 8 structures. Table S6B. Energy ranking for H 2 C 2 S 2 Mn 2 (CO) 8 structures. Table S7. Thermochemistry table for H 2 C 2 S 2 Mn 2 (CO) n systems. Table S8. Orbital energies and HOMO/LUMO gaps for H 2 C 2 S 2 Mn 2 (CO) n . Table S9. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 5 ˑNH 3 structures. Table S10. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 5 ˑPMe 3 structures. Table S11. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 6 ˑNH 3 structures. Table S12. Distance table for the lowest-lying H 2 C 2 S 2 Mn 2 (CO) 6 ˑPMe 3 structures. Table S13. Harmonic ν(CO) vibrational frequencies and infrared intensities for the H 2 C 2 S 2 Mn 2 (CO) n systems. Table S14. Mulliken charges and spin densities H 2 C 2 S 2 Mn 2 (CO) n (n=5, 6, 7). Table S15. TD-DFT-derived spectra: main contributors to the lowest-energy maxima in H 2 C 2 S 2 Mn 2 (CO) 6 and H 2 C 2 S 2 Mn 2 (CO) 6 ˑNH 3 . Electronic Supplementary Material (ESI) for Dalton Transactions. This journal is © The Royal Society of Chemistry 2018