The Electronic Structure and Properties of First-Row Transition Metal Oxides

Area of Science:

• Computational Chemistry
• Atmospheric Science
• Materials Science

Background:

• Diatomic transition metal oxides play a role in atmospheric chemistry.
• Accurate prediction of their properties is crucial for understanding their behavior.
• Previous studies may lack comprehensive data on these species.

Purpose of the Study:

• To investigate the chemical and electronic properties of diatomic 3d transition metal oxides.
• To understand the bonding characteristics and atmospheric science implications of these oxides.
• To provide accurate computational data for ground and low-lying electronic states.

Main Methods:

• High-level coupled-cluster with singles, doubles, and perturbative triples (CCSD(T)) calculations.
• Spin-orbit internally contracted multireference configuration interaction with Davidson correction (icMRCI+Q) calculations.
• Evaluation of Hartree-Fock and PW91 reference orbitals for vibrational frequency calculations.
• Feller-Peterson-Dixon (FPD) level calculations for bond dissociation energies (BDEs).

Main Results:

• Predicted potential energy curves (PECs) for ground and low-lying states of various 3d transition metal oxides (TiO, VO, CrO, MnO, FeO, CoO, CuO, ZnO).
• Spin-orbit effects were found critical for determining ground states of FeO and CoO.
• Calculated vibrational frequencies show good agreement with experimental and literature values, with PW91 orbitals improving accuracy.
• Bond dissociation energies (BDEs) were computed, showing a range from 35.6 kcal/mol (ZnO) to 158.5 kcal/mol (ScO).

Conclusions:

• The study provides a comprehensive set of chemical and electronic properties for diatomic 3d transition metal oxides.
• The findings contribute to a better understanding of bonding and atmospheric relevance.
• The use of PW91 reference orbitals is recommended for accurate vibrational frequency predictions in multireference systems.