Spin multiplicity and symmetry breaking in vanadium-benzene complexes

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Transition metal-based organometallic systems are crucial in catalysis and materials science.
• Accurate theoretical predictions for these systems are challenging due to electron correlation effects.

Purpose of the Study:

• To accurately determine the electronic structure and properties of the vanadium-benzene system.
• To investigate the spin state and energy gaps of vanadium-benzene using high-level computational methods.

Main Methods:

• Accurate quantum Monte Carlo (QMC) calculations were employed.
• A multistage combination of techniques was used to eliminate systematic biases.
• The fixed-node approximation in QMC was utilized.

Main Results:

• The structure, spin multiplicity, ionization energy, and dissociation energy of vanadium-benzene were determined.
• A high-spin state was deduced from total and ionization energies.
• Vastly different spin-dependent electronic gaps were found for the two spin channels.

Conclusions:

• The results significantly differ from previous less accurate calculations.
• High-level many-body methods are essential for predictive calculations of transition metal organometallic systems.
• The findings provide a more accurate understanding of the vanadium-benzene system.