NC-MRSF
Noncollinear Mixed-Reference Spin-Flip TDDFT: Removing the Dependence on High Exact Exchange
M. Mazaherifar, A. Lashkaripour, T. Wang, Y. Xiao, and C. H. Choi
ChemRxiv, 26 October 2026
Publications
Quantum theories. Molecular discoveries.
Research from the Choi group and our collaborators, from electronic-structure methods to photochemistry and molecular dynamics.
Publications
UMRSF gradients
Analytic energy gradients for unrestricted mixed-reference spin-flip time-dependent density functional theory
V. Makhnev, K. Komarov, H. Nakata, S. Lee, and C. H. Choi
Phys. Chem. Chem. Phys. 2026, advance article, 26 October
Analytic NAC
Analytic Derivative Couplings for MRSF-TDDFT: Applications to Nonadiabatic Molecular Dynamics and Conical Intersections
A. Lashkaripour, M. Mazaherifar, and C. H. Choi
ChemRxiv, 21 October 2026
QM/MM and NAMD
Modular integration of MRSF-TDDFT, NAMD, and QM/MM for excited-state dynamics on the OpenQP platform
M. Mazaherifar, W. Park, S. Bonfrate, J. Li, M. Huix-Rotllant, and C. H. Choi
Faraday Discuss. 2026, advance article
QMRSF-DK
Quintet Mixed-Reference Spin-Flip TDDFT with a Dressed Kernel for Four-Orbital Strong Correlation
A. Lashkaripour, S. Lee, M. Huix-Rotllant, and C. H. Choi
ChemRxiv, 25 August 2026
MRSF-TDDFT
Extended Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory for Charge-Transfer State
M. Oh, N. Kim, Y. Jung, C. H. Choi, and S. Lee
J. Chem. Theory Comput. 2026, 22, 6057-6064
Dynamics
Nonadiabatic Dynamics of Uracil in Aqueous Solution from QM/MM in Periodic Boundary Conditions Combined with Mixed-Reference Spin-Flip TDDFT
S. Bonfrate, W. Park, M. Mazaherifar, N. Ferre, C. H. Choi, and M. Huix-Rotllant
J. Chem. Theory Comput. 2026, 22, 9000-9013
Dynamics
Oxidation-State-Controlled Janus Behavior in Eumelanin: Nonadiabatic Branching between Photoprotection and Photoreactivity
M. Farmani and C. H. Choi
J. Phys. Chem. Lett. 2026, 17, 6284-6290
XAS
Benchmarking Core-Level X-ray Absorption with MRSF-TDDFT, RASPT2, and Stochastic GAS Using the XABOOM Set
M. Alías-Rodríguez, F. Montorsi, W. Park, O. Weser, L. Bonfirraro, A. Nenov, M. Garavelli, G. Li Manni, C. H. Choi, F. Segatta, and M. Huix-Rotllant
J. Chem. Theory Comput. 2026, 22, 9572-9591
UMRSF
Eliminating Spin-Asymmetric Orbital Instabilities of Unrestricted MRSF-TDDFT via Selective Jacobi Rotation
V. Makhnev, W. Park, K. Komarov, H. Nakata, S. Lee, and C. H. Choi
J. Chem. Phys. 2026, 164, 134114
Dynamics
Complex and Unusual Excited-State Relaxation Dynamics of 9,9'-Bifluorenylidene Revealed by Comprehensive Time-Resolved Spectroscopy and MRSF-TDDFT Calculations
C. Wang, W. Park, C. H. Choi, S. J. Jang, S. H. Mamillapalli, and J. Xu
J. Phys. Chem. Lett. 2026, 17, 4153-4160
Photochemistry
Impact of Solvation on the Photoisomerization Mechanism of Oxindole Switches with Electron-Donating Substituents
M. Huix-Rotllant, A. Qadeer, D. Roca-Sanjuan, J. Segarra-Marti, and C. H. Choi
Photochem. Photobiol. Sci. 2026, 25, 331-341
Dynamics
Geometry-Sensitive State Ordering and Internal Conversion Equilibrium of Polyenes and Carotenoids
M. Farmani, W. Park, and C. H. Choi
J. Phys. Chem. B 2026, 130, 1774-1782
Reaction Discovery
Autonomous Reaction Discovery of CO2 Capture in Aqueous Ammonia through Active-Learning Neural Networks
H. Nakata and C. H. Choi
J. Chem. Theory Comput. 2026, 22, 1059-1068
Dynamics
Surface Hopping with Fully Correlated Methods
E. G. F. de Miranda, R. S. Mattos, S. Mukherjee, J. M. Toldo, C. H. Choi, M. T. do N. Varella, and M. Barbatti
J. Chem. Theory Comput. 2026, 22, 1-19
Dynamics
Elucidation of Ultrafast Decay, Vibrational Beating, and Slow Decay Processes of Excited Azulene
W. Park, J. M. Lim, S. J. Jang, and C. H. Choi
J. Phys. Chem. Lett. 2026, 17, 257-266
Photochemistry
Tipping the Ultrafast Photochemical Balance of cis-Stilbene
M. Farmani, W. Park, S. Lee, and C. H. Choi
Photochem. Photobiol. Sci. 2025, 24, 955-962
DFTB
Assessing Spin-Flip Time-Dependent Density-Functional-Based Tight-Binding for Describing Z/E Photoisomerization Reactions
M. Huix-Rotllant, W. Park, M. Mazaherifar, and C. H. Choi
Theor. Chem. Acc. 2025, 144, 41
Screening
Addressing the High-Throughput Screening Challenges of Inverted Singlet-Triplet Materials by MRSF-TDDFT
A. Lashkaripour, W. Park, M. Mazaherifar, and C. H. Choi
J. Chem. Theory Comput. 2025, 21, 5661-5668
QMMM
Assessment of Free Energies from Electrostatic Embedding Density Functional Tight Binding-Based/Molecular Mechanics in Periodic Boundary Conditions
S. Bonfrate, W. Park, D. Trejo-Zamora, N. Ferre, C. H. Choi, and M. Huix-Rotllant
J. Comput. Chem. 2025, 46, e70107
Review
MRSF-TDDFT: A New Tool in Quantum Chemistry for Better Understanding Molecules and Materials
S. Lee, W. Park, K. Komarov, V. Mironov, H. Nakata, T. Zeng, M. Huix-Rotllant, and C. H. Choi
Bull. Korean Chem. Soc. 2025, 46, 330-346
Review
Expanding Horizons in Quantum Chemical Studies: The Versatile Power of MRSF-TDDFT
S. Lee, W. Park, and C. H. Choi
Acc. Chem. Res. 2025, 58, 208-217
Review
Time-Dependent DFT: Development of MRSF-TDDFT, Applications, and Future Perspectives
S. Lee, M. Huix-Rotllant, and C. H. Choi
Theoretical and Computational Chemistry 2025, 25, 91-111
Dynamics
Temperature Controlled Decay and Pendulum Dynamics of Green Fluorescent Protein Chromophore
W. Park, J. Oh, J. Kim, S. Lee, J. H. Kim, M. Huix-Rotllant, D. Kim, and C. H. Choi
J. Phys. Chem. Lett. 2024, 15, 11468-11475
OpenQP
OpenQP: A Quantum Chemical Platform Featuring MRSF-TDDFT with an Emphasis on Open-Source Ecosystem
V. Mironov, K. Komarov, J. Li, I. Gerasimov, H. Nakata, M. Mazaherifar, K. Ishimura, W. Park, A. Lashkaripour, M. Oh, M. Huix-Rotllant, S. Lee, and C. H. Choi
J. Chem. Theory Comput. 2024, 20, 9464-9477
UMRSF
UMRSF-TDDFT: Unrestricted Mixed-Reference Spin-Flip-TDDFT
K. Komarov, M. Oh, H. Nakata, S. Lee, and C. H. Choi
J. Phys. Chem. A 2024, 128, 9526-9537
Dynamics
Chemoexcited Formation and Radiationless Decay Dynamics of Firefly Chromophore
M. Farmani, S. Lee, T. Zeng, and C. H. Choi
J. Phys. Chem. Lett. 2024, 15, 9518-9524
Ionization
Toward Consistent Predictions of Core/Valence Ionization Potentials and Valence Excitation Energies by MRSF-TDDFT
W. Park, A. Lashkaripour, K. Komarov, S. Lee, M. Huix-Rotllant, and C. H. Choi
J. Chem. Theory Comput. 2024, 20, 5679-5694
MRSF-TDDFT
Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory: Multireference Advantages with the Practicality of Linear Response Theory
W. Park, K. Komarov, S. Lee, and C. H. Choi
J. Phys. Chem. Lett. 2023, 14, 8896-8908
SOC
Accurate Spin-Orbit Coupling by Relativistic Mixed-Reference Spin-Flip-TDDFT
K. Komarov, W. Park, S. Lee, T. Zeng, and C. H. Choi
J. Chem. Theory Comput. 2023, 19, 953-964
Performance
High-Performance Strategies for the Recent MRSF-TDDFT in GAMESS
K. Komarov, V. Mironov, S. Lee, B. Q. Pham, M. S. Gordon, and C. H. Choi
J. Chem. Phys. 2023, 158, 194105
QMMM
Photochemistry of Thymine in Solution and DNA Revealed by an Electrostatic Embedding QM/MM Combined with Mixed-Reference Spin-Flip TDDFT
M. Huix-Rotllant, K. Schwinn, V. Pomogaev, M. Farmani, N. Ferré, S. Lee, and C. H. Choi
J. Chem. Theory Comput. 2023, 19, 147-156
XAS
Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory for Accurate X-ray Absorption Spectroscopy
W. Park, M. Alías-Rodríguez, D. Cho, S. Lee, M. Huix-Rotllant, and C. H. Choi
J. Chem. Theory Comput. 2022, 18, 6240-6250