Analytical gradients and derivative couplings for the TDDFT-1D method

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate calculation of molecular properties is crucial in chemistry.
• Excited state dynamics and conical intersections are important for understanding photochemical reactions.
• Existing methods may lack efficiency or accuracy for certain problems.

Purpose of the Study:

• To derive and implement analytic gradients and derivative couplings for TDDFT-1D.
• To validate the new implementation against established methods.
• To demonstrate the utility of TDDFT-1D for locating key points on excited state potential energy surfaces.

Main Methods:

• Developed analytic gradients and derivative couplings for TDDFT-1D.
• Validated the implementation by comparing results with finite difference calculations.
• Applied the method to locate optimized geometries and minimum-energy crossing points for S1/S0 states.

Main Results:

• Successfully derived and implemented analytic gradients and derivative couplings for TDDFT-1D.
• The implementation was validated against finite difference values, showing good agreement.
• The method was capable of locating optimized geometries and minimum-energy crossing points on S1/S0 conical seams.

Conclusions:

• The developed TDDFT-1D method provides an efficient and accurate approach for studying excited state properties.
• This implementation facilitates the investigation of photochemical processes and non-adiabatic dynamics.
• The ability to locate critical points on potential energy surfaces is valuable for theoretical chemistry research.