Efficient calculation of the rotational g tensor from auxiliary density functional theory

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Spectroscopy

Background:

• Calculating the rotational g tensor is computationally intensive, often requiring significant CPU time for magnetizability tensor computation.
• Existing theoretical methods may lack efficiency or scalability for complex molecular systems.

Purpose of the Study:

• To present and evaluate the Auxiliary Density Functional Theory (ADFT) with Gauge Including Atomic Orbital (GIAO) methodology for computing rotational g tensors.
• To assess the computational efficiency and accuracy of the ADFT-GIAO approach compared to experimental and other theoretical methods.

Main Methods:

• Implementation of the ADFT-GIAO methodology for rotational g tensor calculations.
• Comparison of ADFT-GIAO results with experimental data and theoretical calculations (Hartree-Fock, coupled-cluster).
• Application of the method to large systems, including carbon nanotube models.

Main Results:

• The ADFT-GIAO methodology significantly reduces CPU time for magnetizability tensor calculations.
• Rotational g tensors computed using ADFT-GIAO show good agreement with experimental values.
• The method demonstrates applicability to large molecular systems with thousands of basis functions.

Conclusions:

• The ADFT-GIAO approach offers a computationally efficient and accurate method for determining rotational g tensors.
• This methodology is a desirable tool for studying molecular properties, particularly for large and complex systems in computational chemistry.