Energies and Spin States of FeS^0/−, FeS₂^0/−, Fe₂S₂^0/−, Fe₃S₄^0/−, and Fe₄S₄^0/− Clusters

Abstract

Abstract The structures and energies of the electronic ground states of the FeS 0/− , FeS 2 0/− , Fe 2 S 2 0/− , Fe 3 S 4 0/− , and Fe 4 S 4 0/− neutral and anionic clusters have been computed systematically with nine computational methods in combination with seven basis sets. The computed adiabatic electronic affinities (AEA) have been compared with available experimental data. Most reasonable agreements between theory and experiment have been found for both hybrid B3LYP and B3PW91 functionals in conjugation with 6‐311+G* and QZVP basis sets. Detailed comparisons between the available experimental and computed AEA data at the B3LYP/6‐311+G* level identified the electronic ground state of 5 Δ for FeS, 4 Δ for FeS − , 5 B 2 for FeS 2 , 6 A 1 for FeS 2 − , 1 A 1 for Fe 2 S 2 , 8 A′ for Fe 2 S 2 − , 5 A′′ for Fe 3 S 4 , 6 A′′ for Fe 3 S 4 − , 1 A 1 for Fe 4 S 4 , and 1 A 2 for Fe 4 S 4 − . In addition, Fe 2 S 2 , Fe 3 S 4 , Fe 3 S 4 − , Fe 4 S 4 , and Fe 4 S 4 − are antiferromagnetic at the B3LYP/6‐311+G* level. The magnetic properties are discussed on the basis of natural bond orbital analysis.