Magnetic properties with multiwavelets and DFT: the complete basis set limit achieved.

Area of Science:

• Computational chemistry
• Quantum mechanics
• Theoretical physics

Background:

• Traditional basis sets like Gaussian-type orbitals and plane waves struggle to reach the basis set limit reliably.
• Multiwavelets offer a novel approach with the potential to overcome these limitations.

Purpose of the Study:

• To implement and apply the linear response formalism using multiwavelets for static magnetic properties at the self-consistent field level.
• To assess the accuracy and benchmarking capabilities of multiwavelets compared to traditional methods.

Main Methods:

• Implementation of multiwavelet basis sets within the linear response formalism.
• Application to static magnetic properties using Hartree-Fock and density functional theories.
• Systematic variation of precision (ε) to demonstrate convergence.

Main Results:

• Multiwavelets consistently improve accuracy with increasing precision, achieving four to five digits.
• Magnetizabilities converge rapidly to the basis set limit.
• Nuclear magnetic resonance shielding tensors present greater challenges for extrapolation.

Conclusions:

• Multiwavelets provide a robust benchmark for computational chemistry, surpassing traditional extrapolation methods.
• The results validate extrapolation methods and enable property-specific schemes.
• This approach allows for the separation of basis set and functional errors in density functional theory.