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Noncollinear and Spin-Flip TDDFT in Multicollinear Approach
Hao Li1, Zhichen Pu1, Qiming Sun2
1College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
Journal of Chemical Theory and Computation
|March 27, 2023
Summary
A new multicollinear approach enhances time-dependent density functional theory (TDDFT) for challenging noncollinear and spin-flip electron excitations. This method addresses numerical instabilities, making advanced excited-state calculations more robust and accessible.
Area of Science:
- Computational Quantum Chemistry
- Electronic Excited States
- Time-Dependent Density Functional Theory (TDDFT)
Background:
- Time-dependent density functional theory (TDDFT) is crucial for studying electron excited states.
- Standard TDDFT calculations for spin-conserving excitations are well-established and routinely performed.
- Noncollinear and spin-flip excitations present significant challenges due to numerical instabilities in existing functionals.
Purpose of the Study:
- To develop and implement a numerically stable approach for noncollinear and spin-flip TDDFT.
- To address the limitations posed by second-order derivatives in conventional noncollinear functionals.
- To introduce the multicollinear approach as a viable solution for challenging TDDFT calculations.
Main Methods:
- Implementation of the novel multicollinear approach within the TDDFT framework.
- Focus on noncollinear and spin-flip excitation calculations.
- Testing the approach with prototypical cases to demonstrate its efficacy.
Main Results:
- Successful implementation of the multicollinear approach in noncollinear and spin-flip TDDFT.
- Demonstration of improved numerical stability compared to existing methods.
- Prototypical tests confirm the viability of the multicollinear approach for advanced excited-state investigations.
Conclusions:
- The multicollinear approach offers a radical solution to the numerical instabilities in noncollinear TDDFT.
- This advancement facilitates more reliable calculations of noncollinear and spin-flip excitations.
- The developed method enhances the applicability of TDDFT for complex electronic structure problems.
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