On the Topological Phase around Conical Intersections with Tamm-Dancoff Linear-Response Time-Dependent Density...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Conical intersections (CIs) are critical features in molecular systems, representing degeneracies between electronic potential energy surfaces.
• Regions near CIs are frequently sampled in nonadiabatic dynamics simulations, necessitating accurate electronic structure methods.
• Previous work investigated the topology and topography of CIs using adiabatic approximation linear-response time-dependent density functional theory (AA LR-TDDFT).

Purpose of the Study:

• To assess the ability of AA LR-TDDFT to reproduce the topological phase accumulated around excited-to-excited state conical intersections.
• To evaluate if AA LR-TDDFT can generate a topological phase from a ground-to-excited state intersection ring, despite incorrect dimensionality.

Main Methods:

• Investigated the topological phase accumulation in protonated formaldimine and pyrazine using AA LR-TDDFT.
• Examined excited-to-excited state conical intersections, considering the use of non-quadratic response nonadiabatic coupling vectors.
• Analyzed the ground-to-excited state intersection ring in protonated formaldimine for topological phase generation.

Main Results:

• AA LR-TDDFT correctly reproduces the topological phase around excited-to-excited state conical intersections, even without appropriate nonadiabatic coupling vectors.
• The method generates a topological phase from the incorrect dimensionality ground-to-excited state intersection ring in protonated formaldimine.
• These findings highlight the robustness of AA LR-TDDFT in describing key topological features of conical intersections.

Conclusions:

• AA LR-TDDFT demonstrates a significant capability in capturing the essential topological properties of conical intersections.
• The method's performance in reproducing topological phases suggests its utility in nonadiabatic dynamics simulations.
• Further investigation into the limitations and applicability of AA LR-TDDFT for various conical intersection scenarios is warranted.