Perspective on a challenge: Predicting the photochemistry of cyclobutanone

J Jiří Janoš (School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,) N Nanna Holmgaard List (School of Chemistry, University of Birmingham 3 , Birmingham B15 2TT,) A Andrew J. Orr-Ewing (School of Chemistry) J Jiří Suchan (Institute for Advanced Computational Science, Stony Brook University 5 , Stony Brook, New York 11794,) M Mario Barbatti (Aix Marseille University, CNRS, ICR 1 , Marseille,) O Olivia Bennett M Marcus Brady (Department of Chemistry, University College London 8 , 20 Gordon St., WC1H 0AJ London,) J Javier Carmona-García (Centre for Computational Chemistry, School of Chemistry) R Rachel Crespo-Otero (Department of Chemistry) J Julien Eng (Chemistry – School of Natural and Environmental Sciences) O O. Jonathan Fajen (Department of Chemistry and The PULSE Institute, Stanford University 10 , Stanford, California 94305,) M Marco Garavelli (Dipartimento di Chimica industriale “Toso Montanari”, Università di Bologna, Via Piero Gobetti 85, Bologna 40129, Italy) S Sandra Gómez (Departamento de Química, Módulo 13, Universidad Autónoma de Madrid 13 , 28049 Madrid,) A Alice E. Green (EaStCHEM School of Chemistry) F Federico J. Hernández (Department of Chemistry, Queen Mary University of London. Mile End Road, London. E1 4NS, U.K.) D Daniel Hollas (School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,) L Lewis Hutton (Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford 16 , Oxford OX1 3QZ,) L Lea M. Ibele (Aix Marseille University, CNRS, ICR) A Adam Kirrander (Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford 16 , Oxford OX1 3QZ,) Z Zhenggang Lan (MOE Key Laboratory of Environmental Theoretical Chemistry, SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University 3 , Guangzhou 510006,) Y Yorick Lassmann (School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,) J Joseph E. Lawrence (Simons Center for Computational Physical Chemistry, New York University 18 , New York, New York 10003,) B Benjamin G. Levine (Department of Chemistry) D Dmitry V. Makhov (School of Chemistry, University of Leeds 21 , Leeds LS2 9JT,) J Jonathan R. Mannouch (The Max Planck Institute for the Structure and Dynamics of Matter 4 , 22761 Hamburg,) X Xincheng Miao (Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg 23 , Emil-Fischer-Straße 42, 97074 Würzburg,) R Roland Mitric (Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer Str. 42, 97074 Würzburg, Germany) S Shane M. Parker (Department of Chemistry, Case Western Reserve University 24 , Cleveland, Ohio 44106,) T Thomas J. Penfold (Chemistry – School of Natural and Environmental Sciences) J Jiawei Peng (SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, School of Environment, South China Normal University 17 , Guangzhou 510006,) J Jeremy O. Richardson (Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, Zurich CH-8093, Switzerland) D Dmitrii Shalashilin (School of Chemistry, University of Leeds 21 , Leeds LS2 9JT,) P Petr Slavíček (Department of Physical Chemistry, University of Chemistry and Technology 7 , Technická 5, Prague 6 166 28,) K K. Eryn Spinlove (Department of Chemistry, University College London 8 , 20 Gordon St., WC1H 0AJ London,) P Patricia Vindel-Zandbergen (Department of Chemistry, New York University 19 , New York, New York 10003,) F Federica Agostini S Sara Bonella (Centre Européen de Calcul Atomique et Moléculaire) T Todd J. Martinez (Department of Chemistry) G Graham A. Worth (Department of Chemistry, University College London 9 , 20 Gordon St., London WC1H 0AJ,) B Basile F. E. Curchod (School of Chemistry, Cantock’s Close)

Abstract

This Perspective is part of a Special Topic that explored the maturity of nonadiabatic molecular dynamics for predicting photochemical processes. In 2023, a prediction challenge was issued to the community of computational photochemists to simulate the photochemistry of cyclobutanone, photoexcited at 200 nm, and the resulting time-resolved mega-electronvolt ultrafast electron diffraction (MeV-UED) signal. The challenge attracted 15 theoretical predictions from more than 70 researchers, employing a wide range of strategies for electronic structure and nonadiabatic molecular dynamics to predict the time-resolved MeV-UED signal before the experiment had been conducted at SLAC (Stanford, USA). The MeV-UED instrument at Shanghai Jiao Tong University was also used to provide a second independent time-resolved MeV-UED signal for the photochemistry of cyclobutanone. This Perspective discusses the various approaches and strategies used by the participants to predict the photochemistry of cyclobutanone. This work also summarizes the strengths and weaknesses of various methods used for photoexcitation, electronic structure, nonadiabatic dynamics, and calculation of observables, as agreed by the participants during a CECAM workshop dedicated to the results of the challenge and organized in Lausanne in April 2025. This Perspective also collects all the predicted time-resolved MeV-UED signals into a single figure, together with the experimental signal. The challenge (i) demonstrated the qualitative predictive power of nonadiabatic molecular dynamics and (ii) underscored the impact of electronic-structure theory on the outcome of the excited-state dynamics and the need for its careful benchmarking. This effort allowed the community to share practical strategies to perform nonadiabatic dynamics (discussed in the present Perspective) and constitutes a “calibration” exercise for computational photochemistry.

Article Details

Volume / Issue Vol. 165, Issue 2
Published July 14, 2026
ISSN 0021-9606
Publisher American Institute of Physics

Journal Info

The Journal of Chemical Physics

American Institute of Physics

ISSN: 0021-9606 Physical Sciences

Authors (40)

J

Jiří Janoš

School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,

N

Nanna Holmgaard List

School of Chemistry, University of Birmingham 3 , Birmingham B15 2TT,

A

Andrew J. Orr-Ewing

School of Chemistry

J

Jiří Suchan

Institute for Advanced Computational Science, Stony Brook University 5 , Stony Brook, New York 11794,

M

Mario Barbatti

Aix Marseille University, CNRS, ICR 1 , Marseille,

O

Olivia Bennett

M

Marcus Brady

Department of Chemistry, University College London 8 , 20 Gordon St., WC1H 0AJ London,

J

Javier Carmona-García

Centre for Computational Chemistry, School of Chemistry

R

Rachel Crespo-Otero

Department of Chemistry

J

Julien Eng

Chemistry – School of Natural and Environmental Sciences

O

O. Jonathan Fajen

Department of Chemistry and The PULSE Institute, Stanford University 10 , Stanford, California 94305,

M

Marco Garavelli

Dipartimento di Chimica industriale “Toso Montanari”, Università di Bologna, Via Piero Gobetti 85, Bologna 40129, Italy

S

Sandra Gómez

Departamento de Química, Módulo 13, Universidad Autónoma de Madrid 13 , 28049 Madrid,

A

Alice E. Green

EaStCHEM School of Chemistry

F

Federico J. Hernández

Department of Chemistry, Queen Mary University of London. Mile End Road, London. E1 4NS, U.K.

D

Daniel Hollas

School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,

L

Lewis Hutton

Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford 16 , Oxford OX1 3QZ,

L

Lea M. Ibele

Aix Marseille University, CNRS, ICR

A

Adam Kirrander

Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford 16 , Oxford OX1 3QZ,

Z

Zhenggang Lan

MOE Key Laboratory of Environmental Theoretical Chemistry, SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, School of Environment, South China Normal University 3 , Guangzhou 510006,

Y

Yorick Lassmann

School of Chemistry, University of Bristol 1 , Bristol BS8 1TS,

J

Joseph E. Lawrence

Simons Center for Computational Physical Chemistry, New York University 18 , New York, New York 10003,

B

Benjamin G. Levine

Department of Chemistry

D

Dmitry V. Makhov

School of Chemistry, University of Leeds 21 , Leeds LS2 9JT,

J

Jonathan R. Mannouch

The Max Planck Institute for the Structure and Dynamics of Matter 4 , 22761 Hamburg,

X

Xincheng Miao

Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg 23 , Emil-Fischer-Straße 42, 97074 Würzburg,

R

Roland Mitric

Institut für Physikalische und Theoretische Chemie, Universität Würzburg, Emil-Fischer Str. 42, 97074 Würzburg, Germany

S

Shane M. Parker

Department of Chemistry, Case Western Reserve University 24 , Cleveland, Ohio 44106,

T

Thomas J. Penfold

Chemistry – School of Natural and Environmental Sciences

J

Jiawei Peng

SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, School of Environment, South China Normal University 17 , Guangzhou 510006,

J

Jeremy O. Richardson

Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 3, Zurich CH-8093, Switzerland

D

Dmitrii Shalashilin

School of Chemistry, University of Leeds 21 , Leeds LS2 9JT,

P

Petr Slavíček

Department of Physical Chemistry, University of Chemistry and Technology 7 , Technická 5, Prague 6 166 28,

K

K. Eryn Spinlove

Department of Chemistry, University College London 8 , 20 Gordon St., WC1H 0AJ London,

P

Patricia Vindel-Zandbergen

Department of Chemistry, New York University 19 , New York, New York 10003,

F

Federica Agostini

S

Sara Bonella

Centre Européen de Calcul Atomique et Moléculaire

T

Todd J. Martinez

Department of Chemistry

G

Graham A. Worth

Department of Chemistry, University College London 9 , 20 Gordon St., London WC1H 0AJ,

B

Basile F. E. Curchod

School of Chemistry, Cantock’s Close