Calculation of static and dynamic linear magnetic response in approximate time-dependent density functional theory

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Spectroscopy

Background:

• Accurate calculation of molecular magnetic properties is crucial for understanding chemical behavior and interactions.
• Existing methods often face challenges with gauge-origin independence and computational efficiency.

Purpose of the Study:

• To implement and validate time-dependent density functional calculations for advanced magnetic response properties.
• To investigate frequency-dependent magnetic dipole-magnetic dipole polarizability and linear magnetic response.
• To compute linear intensity differential (LID) including dynamic dipole magnetizability.

Main Methods:

• Time-dependent density functional theory (TD-DFT) with density fitting.
• Employing time-periodic magnetic-field-dependent basis functions and the dipole velocity gauge.
• Including explicit density-fit derivatives of the Coulomb potential for gauge-origin independence.

Main Results:

• Calculated static and dynamic magnetic dipole-magnetic dipole polarizabilities for small molecules.
• Computed LID for SF6 and origin-invariant linear magnetic response dispersion curves for M-hexahelicene.
• Presented comparisons of linear magnetic response and magnetic dipole-magnetic dipole polarizability for H2O and SF6 across a broad frequency range.

Conclusions:

• The implemented TD-DFT approach provides accurate and gauge-origin independent calculations of molecular magnetic properties.
• The study demonstrates the utility of these methods for characterizing dynamic magnetic responses.
• Findings contribute to a deeper understanding of molecular magnetism and spectroscopy.