title: Femtosecond charge and molecular dynamics of I-containing organic molecules induced by intense X-ray free-electron laser pulses.
abstract: We studied the electronic and nuclear dynamics of I-containing organic molecules induced by intense hard X-ray pulses at the XFEL facility SACLA in Japan. The interaction with the intense XFEL pulse causes absorption of multiple X-ray photons by the iodine atom, which results in the creation of many electronic vacancies (positive charges) via the sequential electronic relaxation in the iodine, followed by intramolecular charge redistribution. In a previous study we investigated the subsequent fragmentation by Coulomb explosion of the simplest I-substituted hydrocarbon, iodomethane (CH3I). We carried out three-dimensional momentum correlation measurements of the atomic ions created via Coulomb explosion of the molecule and found that a classical Coulomb explosion model including charge evolution (CCE-CE model), which accounts for the concerted dynamics of nuclear motion and charge creation/charge redistribution, reproduces well the observed momentum correlation maps of fragment ions emitted after XFEL irradiation. Then we extended the study to 5-iodouracil (C4H3IN2O2, 5-IU), which is a more complex molecule of biological relevance, and confirmed that, in both CH3I and 5-IU, the charge build-up takes about 10 fs, while the charge is redistributed among atoms within only a few fs. We also adopted a self-consistent charge density-functional based tight-binding (SCC-DFTB) method to treat the fragmentations of highly charged 5-IU ions created by XFEL pulses. Our SCC-DFTB modeling reproduces well the experimental and CCE-CE results. We have also investigated the influence of the nuclear dynamics on the charge redistribution (charge transfer) using nonadiabatic quantum-mechanical molecular dynamics (NAQMD) simulation. The time scale of the charge transfer from the iodine atomic site to the uracil ring induced by nuclear motion turned out to be only ∼5 fs, indicating that, besides the molecular Auger decay in which molecular orbitals delocalized over the iodine site and the uracil ring are involved, the nuclear dynamics also play a role for ultrafast charge redistribution. The present study illustrates that the CCE-CE model as well as the SCC-DFTB method can be used for reconstructing the positions of atoms in motion, in combination with the momentum correlation measurement of the atomic ions created via XFEL-induced Coulomb explosion of molecules.
authors: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan and RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan. ueda@tagen.tohoku.ac.jp.
authors: K
authors: K
authors: Nagaya
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: K
authors: K
authors: Motomura
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan and Department of Physics and Astronomy, University of Turku, FI-20014, Finland.
authors: E
authors: E
authors: Kukk
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors: Y
authors: Y
authors: Takahashi
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan and Department of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
authors: K
authors: K
authors: Yamazaki
authors: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan and Research Center for Condensed Matter Physics, Hiroshima Institute of Technology, Hiroshima 731-5193, Japan.
authors: S
authors: S
authors: Ohmura
authors: RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan. ueda@tagen.tohoku.ac.jp and Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: H
authors: H
authors: Fukuzawa
authors: RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan. ueda@tagen.tohoku.ac.jp and Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
authors: S
authors: S
authors: Wada
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: S
authors: S
authors: Mondal
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: T
authors: T
authors: Tachibana
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: Y
authors: Y
authors: Ito
authors: Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
authors: R
authors: R
authors: Koga
authors: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: T
authors: T
authors: Sakai
authors: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: K
authors: K
authors: Matsunami
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors: K
authors: K
authors: Nakamura
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors: M
authors: M
authors: Kanno
authors: J.R. Macdonald Laboratory, Department of Physics, Kansas State University, 66506 Manhattan, KS, USA.
authors: A
authors: A
authors: Rudenko
authors: Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex, France.
authors: C
authors: C
authors: Nicolas
authors: Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex, France and School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China.
authors: X-J
authors: XJ
authors: Liu
authors: Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, FR-91192 Gif-sur-Yvette Cedex, France and Extreme Light Infrastructure - Nuclear Physics (ELI-NP), "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov, Romania.
authors: C
authors: 0000-0002-8302-7158
authors: C
authors: Miron
authors: Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210 Shanghai, China.
authors: Y
authors: Y
authors: Zhang
authors: Shanghai Advanced Research Institute, Chinese Academy of Sciences, 201210 Shanghai, China.
authors: Y
authors: Y
authors: Jiang
authors: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 201800 Shanghai, China.
authors: J
authors: J
authors: Chen
authors: Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang, 37673, South Korea and Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Init., Pohang, 37673, South Korea.
authors: M
authors: M
authors: Anand
authors: Department of Physics, Center for Attosecond Science and Technology, Pohang University of Science and Technology, Pohang, 37673, South Korea and Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Init., Pohang, 37673, South Korea.
authors: D E
authors: DE
authors: Kim
authors: Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.
authors: K
authors: K
authors: Tono
authors: RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan. ueda@tagen.tohoku.ac.jp and Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.
authors: M
authors: M
authors: Yabashi
authors: Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
authors: M
authors: M
authors: Yao
authors: Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
authors: H
authors: H
authors: Kono
authors: RIKEN SPring-8 Center, Sayo, Hyogo 679-5148, Japan. ueda@tagen.tohoku.ac.jp and Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan.
authors: K
authors: K
authors: Ueda