Researcher basic information

• PhD (Science), Tokyo Metropolitan University, Mar. 2020

• https://researchmap.jp/asunaga?lang=en

• https://orcid.org/0000-0002-3802-680X
• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201901008562587787
• https://scholar.google.co.jp/citations?user=Rchm_igAAAAJ&hl=en&oi=ao

• https://orcid.org/0000-0002-3802-680X

• 201901008562587787

• quantum chemistry
• relativistic quantum chemistry
• Molecular spectroscopy
• quantum electrodynamics effects in chemistry
• CP violation
• molecular physics
• atomic physics

• Nanotechnology/Materials, Fundamental physical chemistry
• Natural Science, Semiconductors, optical properties of condensed matter and atomic physics

Research activity information

• Mar. 2026, Editors' Suggestion (Phys. Rev. A) "Rotational splittings in diatomic molecules of interest to searches for new physics"
  Ayaki Sunaga;Timo Fleig, Official journal
• Feb. 2023, Kyoto university Fukui Institute for Fundamental Chemistry, Kenichi Fukui Award (7th)
  Ayaki Sunaga, Quantum electrodynamics effects in chemistry and the search for CP-violation using molecules
• Oct. 2022, Featured article (J. Chem. Phys.)
  "4-component relativistic Hamiltonian with effective QED potentials for molecular calculations"
  Ayaki Sunaga;Maen Salman;Trond Saue, Official journal

• Vibrational infrared and Raman spectra of the methanol molecule with equivariant neural-network property surfaces
  Ayaki Sunaga; Albert P. Bartók; Edit Mátyus
  Physical Chemistry Chemical Physics, 28, 12299, 12313, 21 Apr. 2026, [Peer-reviewed], [Lead author], ［Internationally co-authored］, [International Magazine]
  Scientific journal, Electric dipole and polarizability surfaces are developed for the methanol molecule using {\it ab initio} electronic structure data, computed at the CCSD/aug-cc-pVTZ level of theory, and equivariant neural networks. These property surfaces are used to compute vibrational infrared and Raman intensities up to the OH stretching fundamental vibration. The intensity computations use the vibrational energies and wave functions obtained in continued variational vibrational computations from earlier work [J. Chem. Phys. 163, 064101 (2025)]. The vibrational representation accounts for the large-amplitude torsion and uses curvilinear normal coordinates for the small-amplitude modes, allowing truncation of the vibrational basis set and the integration grid.
• Orders-of-magnitude improvement in precision spectroscopy of an inner-shell orbital clock transition in neutral ytterbium
  Taiki Ishiyama; Koki Ono; Hokuto Kawase; Tetsushi Takano; Reiji Asano; Ayaki Sunaga; Yasuhiro Yamamoto; Minoru Tanaka; Yoshiro Takahashi
  Nature Photonics, 20, 504, 511, 20 Mar. 2026, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Rotational splittings in diatomic molecules of interest to searches for new physics
  Ayaki Sunaga; Timo Fleig
  Physical Review A, 113, 032809, American Physical Society (APS), 05 Mar. 2026, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Ionization potential of radium monofluoride
  S. G. Wilkins; H. A. Perrett; S. M. Udrescu; A. A. Kyuberis; L. F. Pašteka; M. Au; I. Belošević; R. Berger; C. L. Binnersley; M. L. Bissell; A. Borschevsky; A. A. Breier; A. J. Brinson; K. Chrysalidis; T. E. Cocolios; B. S. Cooper; R. P. de Groote; A. Dorne; E. Eliav; R. W. Field; K. T. Flanagan; S. Franchoo; R. F. Garcia Ruiz; K. Gaul; S. Geldhof; T. F. Giesen; F. P. Gustafsson; D. Hanstorp; R. Heinke; Á. Koszorús; S. Kujanpää; L. Lalanne; G. Neyens; M. Nichols; J. R. Reilly; C. M. Ricketts; S. Rothe; A. Sunaga; B. van den Borne; A. R. Vernon; Q. Wang; J. Wessolek; F. Wienholtz; X. F. Yang; Y. Zhou; C. Zülch
  Physical Review Research, 8, L012012, 13 Jan. 2026, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal,
  The ionization potential (IP) of radium monofluoride (RaF) was measured to be 4.969(2)[10] eV, revealing a relativistic enhancement in the series of alkaline earth monofluorides. The results are in agreement with a relativistic coupled-cluster prediction of 4.981(7) eV, incorporating up to quantum electrodynamics corrections. Using the same computational methodology, an improved calculation for the dissociation energy
  
  (
  
  D
  0
  
  )
  
  of 5.54(5) eV is presented. This confirms that RaF joins the group of diatomic molecules for which
  
  
  
  D
  0
  
  >
  IP
  
  
  , paving the way for precision control and interrogation of its Rydberg states.
  
• Exact quantum dynamics of methanol: Full-dimensional ab initio potential energy surface of spectroscopic quality and variational vibrational states
  Ayaki Sunaga; Tibor Győri; Gábor Czakó; Edit Mátyus
  The Journal of Chemical Physics, 163, 6, 064101, 14 Aug. 2025, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Hyperfine Rovibrational States of H3+ in a Weak External Magnetic Field
  Gustavo Avila; Ayaki Sunaga; Stanislav Komorovsky; Edit Mátyus
  Physical Review Letters, 135, 4, 043003, American Physical Society (APS), 22 Jul. 2025, [Peer-reviewed], [International Magazine]
  Scientific journal
• Theoretical determination of the ionization potentials of ScF, YF, LaF, and AcF
  A. A. Kyuberis; L. F. Pašteka; E. Eliav; A. Sunaga; M. Au; S. G. Wilkins; A. Borschevsky
  Physical Review A, 111, 4, 042823, American Physical Society (APS), 23 Apr. 2025, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  Scientific journal
• Strong parity-violation effects induced by large-amplitude motions: A quantum-dynamics study of substituted chiral methanols
  Ayaki Sunaga
  The Journal of Chemical Physics, 162, 6, 064302, 10 Feb. 2025, [Peer-reviewed], [Lead author, Last author, Corresponding author], [International Magazine]
  Scientific journal
• Structure and Excitation Spectra of Third-Row Transition Metal Hexafluorides Based on Multi-Reference Exact Two-Component Theory
  Ayaki Sunaga
  Inorganic Chemistry, 63, 39, 18355, 18364, American Chemical Society (ACS), 16 Sep. 2024, [Peer-reviewed], [Lead author, Last author, Corresponding author], [International Magazine]
  Scientific journal
• Variational Vibrational States of Methanol (12D)
  Ayaki Sunaga; Gustavo Avila; Edit Mátyus
  Journal of Chemical Theory and Computation, 20, 18, 8100, 8117, 30 Aug. 2024, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Theoretical determination of the ionization potentials of CaF, SrF, and BaF
  A. A. Kyuberis; L. F. Pašteka; E. Eliav; H. A. Perrett; A. Sunaga; S. M. Udrescu; S. G. Wilkins; R. F. Garcia Ruiz; A. Borschevsky
  Physical Review A, 109, 022813, 22 Feb. 2024, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  We present a comprehensive theoretical study of the ionization potentials of
  the MF (M = Sc, Y, La, Ac) molecules using the state-of-the-art relativistic
  coupled cluster approach with single, double, and perturbative triple
  excitations (CCSD(T)). We have further corrected our results for higherorder
  excitations (up to full triples), the QED self-energy and vacuum-polarization
  contributions. We have extensively investigated the effect of the various
  computational parameters on the calculated ionization potentials, allowing us
  to assign realistic uncertainties to our predictions.
• Measuring the nuclear magnetic quadrupole moment of optically trapped ytterbium atoms in the metastable state
  Ayaki Sunaga; Yuiki Takahashi; Amar Vutha; Yoshiro Takahashi
  New Journal of Physics, 26, 2, 023023, 023023, IOP Publishing, 01 Feb. 2024, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  Scientific journal, Abstract
  
  We propose a scheme to measure a nuclear magnetic quadrupole moment (MQM), a $\mathcal{CP}$-violating electromagnetic moment that appears in the nuclear sector, using the long-lived $^3P_2$ metastable state in neutral ¹⁷³Yb atoms. Laser-cooling and trapping techniques enable us to prepare ultracold ¹⁷³Yb atoms in the $^3P_2$ state trapped in an optical lattice or an optical tweezer array, providing an ideal experimental platform with long spin coherence time. In addition, our relativistic configuration interaction calculation for the $^3P_2$ electronic wavefunction reveals a large magnetic field gradient generated by the atomic electrons in this state, which amplifies the measurable effect of an MQM. Our scheme could lead to an improvement of more than one order of magnitude in MQM sensitivity compared to the best previous measurement (Murthy $et~al$ 1989 Phys. Rev. Lett.63, 965).
• Enhancement of Parity-Violating Energy Difference of CHFClBr, CHFClI, and CHFBrI by Breaking the Cancellation among Valence Orbital Contributions
  Naoya Kuroda; Ayaki Sunaga; Masato Senami
  Journal of the Physical Society of Japan, 92, 12, 124301, Physical Society of Japan, 06 Nov. 2023, [Peer-reviewed]
  English, Scientific journal
• Observation of an Inner-Shell Orbital Clock Transition in Neutral Ytterbium Atoms
  Taiki Ishiyama; Koki Ono; Tetsushi Takano; Ayaki Sunaga; Yoshiro Takahashi
  Physical Review Letters, 130, 15, 153402, American Physical Society (APS), 14 Apr. 2023, [Peer-reviewed]
  Scientific journal
• Crystallographic and/or magnetic properties of neutral and cationic uranium(IV) sandwiched phthalocyanine complexes
  Chihiro Tabata; Hirohito Watanabe; Kenji Shirasaki; Ayaki Sunaga; Takamitsu Fukuda; Dexin Li; Tomoo Yamamura
  Journal of Molecular Structure, 1277, 134870, 134870, Elsevier BV, Apr. 2023, [Peer-reviewed]
  English, Scientific journal
• Diffuse Basis Functions for Relativistic s and d Block Gaussian Basis Sets
  Kenneth G. Dyall; Paweł Tecmer; Ayaki Sunaga
  Journal of Chemical Theory and Computation, 19, 1, 198, 210, American Chemical Society (ACS), 10 Jan. 2023, [Peer-reviewed]
  English, Scientific journal
• Linearity and Chemical Bond of UO2(2+) Revisited: A Comparison Study with UN2 and UE2(2+) (E = S, Se, and Te) Based on Relativistic Calculations
  Ayaki Sunaga; Chihiro Tabata; Tomoo Yamamura
  The Journal of Physical Chemistry A, 126, 46, 8606, 8617, American Chemical Society (ACS), 24 Nov. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• 4-component relativistic Hamiltonian with effective QED potentials for molecular calculations
  Ayaki Sunaga; Maen Salman; Trond Saue
  The Journal of Chemical Physics, 157, 16, 164101, AIP Publishing, 28 Oct. 2022, [Peer-reviewed], [Lead author]
  Scientific journal, We report the implementation of effective quantum electrodynamics (QED) potentials for all-electron four-component relativistic molecular calculations using the DIRAC code. The potentials are also available for two-component calculations, being properly picture-change transformed. The latter point is important; we demonstrate through atomic calculations that picture-change errors are sizable. Specifically, we have implemented the Uehling potential [E. A. Uehling, Phys. Rev. 48, 55 (1935)] for vacuum polarization and two effective potentials [P. Pyykkö and L.-B. Zhao, J. Phys. B: At., Mol. Opt. Phys. 36, 1469 (2003) and V. V. Flambaum and J. S. M. Ginges, Phys. Rev. A 72, 052115 (2005)] for electron self-energy. We provide extensive theoretical background for these potentials, hopefully reaching an audience beyond QED specialists. We report the following sample applications: (i) We first confirm the conjecture of P. Pyykkö that QED effects are observable for the AuCN molecule by directly calculating ground-state rotational constants B₀ of the three isotopomers studied by microwave spectroscopy; QED brings the corresponding substitution Au–C bond length r _s from 0.23 to 0.04 pm agreement with experiment. (ii) In regard to spectroscopic constants of van der Waals dimers M₂ (M = Hg, Rn, Cn, Og), QED induces bond length expansions on the order of 0.15(0.30) pm for row 6(7) dimers. (iii) We confirm that there is a significant change of valence s population of Pb in the reaction PbH₄ → PbH₂ + H₂, which is thereby a good candidate for observing QED effects in chemical reactions, as proposed in [K. G. Dyall et al., Chem. Phys. Lett. 348, 497 (2001)]. We also find that whereas in PbH₄ the valence 6 s_1/2 population resides in bonding orbitals, it is mainly found in nonbonding orbitals in PbH₂. QED contributes 0.32 kcal/mol to the reaction energy, thereby reducing its magnitude by −1.27%. For corresponding hydrides of superheavy flerovium, the electronic structures are quite similar. Interestingly, the QED contribution to the reaction energy is of quite similar magnitude (0.35 kcal/mol), whereas the relative change is significantly smaller (−0.50%). This curious observation can be explained by the faster increase in negative vacuum polarization over positive electron self-energy contributions as a function of nuclear charge.
• Sr(ii) extraction by crown ether in HFC: entropy driven mechanism through H2PFTOUD
  Kenji Shirasaki; Mitsuie Nagai; Masahiko Nakase; Chihiro Tabata; Ayaki Sunaga; Tsuyoshi Yaita; Tomoo Yamamura
  RSC Advances, 12, 41, 26922, 26933, Royal Society of Chemistry (RSC), Aug. 2022, [Peer-reviewed]
  Scientific journal, The solvent extraction of Sr(ii) was carried out using DCH18C6, and two HFC mixed solvents composed of organic solvents and HFC-43 (HFC-43: 1,1,1,2,2,3,4,5,5,5-decafluoropentane), and two acids (nitric acid and H₂PFTOUD).
• Homogeneity of (U, M)O2 (M = Th, Np) prepared by supercritical hydrothermal synthesis
  Kenji Shirasaki; Chihiro Tabata; Ayaki Sunaga; Hironori Sakai; Dexin Li; Mariko Konaka; Tomoo Yamamura
  Journal of Nuclear Materials, 563, 153608, 153608, May 2022, [Peer-reviewed]
  English, Scientific journal
• Spectroscopic and electric properties of the TaO+ molecule ion for the search of new physics: A platform for identification and state control
  Ayaki Sunaga; Timo Fleig
  Journal of Quantitative Spectroscopy and Radiative Transfer, 288, 108229, Elsevier {BV}, 26 Apr. 2022, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• Enhancement of the parity-violating energy difference of H2X2 molecules by electronic excitation
  Naoya Kuroda; Takumi Oho; Masato Senami; Ayaki Sunaga
  Physical Review A, 105, 1, 012820, American Physical Society ({APS}), 31 Jan. 2022, [Peer-reviewed]
  English, Scientific journal
• Influence of additives on low-temperature hydrothermal synthesis of UO_2+x and ThO₂
  Chihiro Tabata; Kenji Shirasaki; Hironori Sakai; Ayaki Sunaga; Dexin Li; Mariko Konaka; Tomoo Yamamura
  CrystEngComm, 24, 19, 3637, 3648, 2022, [Peer-reviewed]
  English, Scientific journal
• Hydrofluorocarbon Diluent for CMPO Without Third Phase Formation: Extraction of Uranium(VI) and Lanthanide(III) Ions
  Chihiro Tabata; Masahiko Nakase; Miki Harigai; Kenji Shirasaki; Ayaki Sunaga; Tomoo Yamamura
  Separation Science and Technology, 57, 7, 1, 14, Informa {UK} Limited, 19 Sep. 2021, [Peer-reviewed]
  English, Scientific journal
• Towards highly accurate calculations of parity violation in chiral molecules: relativistic coupled-cluster theory including QED-effects
  Ayaki Sunaga; Trond Saue
  Molecular Physics, (Special Issue in Honour of John Stanton: Theory Meets Experiment), e1974592, Informa UK Limited, 10 Sep. 2021, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Supercritical hydrothermal synthesis of UO2+x: stoichiometry, crystal shape and size, and homogeneity observed using 23Na-NMR spectroscopy of (U, Na)O2+x
  Chihiro Tabata; Kenji Shirasaki; Ayaki Sunaga; Hironori Sakai; Dexin Li; Mariko Konaka; Tomoo Yamamura
  CrystEngComm, 23, 48, 8660, 8672, 2021, [Peer-reviewed]
  English, Scientific journal
• The DIRAC code for relativistic molecular calculations
  Trond Saue; Radovan Bast; André Severo Pereira Gomes; Hans Jørgen Aa. Jensen; Lucas Visscher; Ignacio Agustín Aucar; Roberto Di Remigio; Kenneth G. Dyall; Ephraim Eliav; Elke Fasshauer; Timo Fleig; Loïc Halbert; Erik Donovan Hedegård; Benjamin Helmich-Paris; Miroslav Iliaš; Christoph R. Jacob; Stefan Knecht; Jon K. Laerdahl; Marta L. Vidal; Malaya K. Nayak; Małgorzata Olejniczak; Jógvan Magnus Haugaard Olsen; Markus Pernpointner; Bruno Senjean; Avijit Shee; Ayaki Sunaga; Joost N. P. van Stralen
  The Journal of Chemical Physics, 152, 20, 204104, 204104-18, AIP Publishing, 29 May 2020, [Peer-reviewed]
  Scientific journal
• Relativistic coupled-cluster study of diatomic metal-alkali-metal molecules for electron electric dipole moment searches
  A. Sunaga; M. Abe; V. S. Prasannaa; T. Aoki; M. Hada
  J. Phys. B At. Mol. Opt. Phys., 53, 15102, 15102-11, Dec. 2019, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Merits of heavy-heavy diatomic molecules for electron electric-dipole-moment searches
  A. Sunaga; M. Abe; M. Hada; B. P. Das
  Physical Review A, 99, 6, 062506, American Physical Society (APS), 11 Jun. 2019, [Peer-reviewed], [Lead author, Corresponding author]
  Scientific journal
• The Role of Relativistic Many-Body Theory in Electron Electric Dipole Moment Searches Using Cold Molecules
  Srinivasa Prasannaa; Ayaki Sunaga; M. Abe; Masahiko Hada; N. Shitara; A. Sakurai; B. P. Das
  Atoms, 7, 2, 58, 58, {MDPI} {AG}, 10 Jun. 2019, [Peer-reviewed]
  English, Scientific journal
• Ultracold mercury–alkali-metal molecules for electron-electric-dipole-moment searches
  Ayaki Sunaga
  Physical Review A, 99, 040501, 040501-6, 05 Apr. 2019, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Enhancement factors of parity- and time-reversal-violating effects for monofluorides
  A. Sunaga; V. S. Prasannaa; M. Abe; M. Hada; B. P. Das
  Physical Review A, 98, 4, 042511, 042511-6, American Physical Society ({APS}), 22 Oct. 2018, [Peer-reviewed], [Lead author, Corresponding author]
  English, Scientific journal
• Theoretical Study of Formulation of Hyperfine Coupling Constant in Four-component Relativistic Framework
  A. Sunaga; M. Abe; M. Hada
  J. Comput. Chem. Jpn., 16, 4, 81, 82, Oct. 2017, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Analysis of large effective electric fields of weakly polar molecules for electron electric-dipole-moment searches
  A. Sunaga; M. Abe; M. Hada; B. P. Das
  Phys. Rev. A, 95, 1, 012502, 012502-6, Jan. 2017, [Peer-reviewed], [Lead author]
  English, Scientific journal
• Relativistic coupled-cluster calculation of the electron-nucleus scalar-pseudoscalar interaction constant Ws in YbF
  A. Sunaga; M. Abe; M. Hada; B. P. Das
  Physical Review A, 93, 4, 042507, 18 Apr. 2016, [Peer-reviewed], [Lead author]
  Scientific journal

• DIRAC26
  A. S. P. Gomes; T. Saue; L. Visscher; H. J. A. Jensen; R. Bas; M. Abe; I. A. Aucar; J. J. Aucar; V. Bakken; J. Brandejs; C. Chibueze; S. Dubillard; K. G. Dyall; U. Ekström; E. Eliav; T. Enevoldsen; G. Fabbro; E. Fasshauer; T. Fleig; O. Fossgaard; K. J. Gaul; L. Halber; E. D. Hedegård; T. Helgaker; B. Helmich-Paris; J. Henriksson; M. van Horn; M. Ilias; S. Iwamuro; C. Jacob; S. Knech; S. Komorovsky; O. Kullie; J. K. Laerdahl; C. V. Larsen; E. D. Larsson; M. Le; Y. S. Lee; T. Lejeune; N. H. Lis; Y. Masuda; H. Nataraj; M. K. Nayak; K. Noda; P. Norman; A. Nyvang; M. Olejniczak; J. Olsen; J. M. H. Olsen; A. Papadopoulos; Y. C. Park; J. K. Pedersen; M. Pernpointner; J. Pototschnig; R. Di Remigio Eikås; M. Repisky; K. Ruud; B. Senjean; A. Shee; J. Sikkema; A. Sunaga; A. J. Thorvaldsen; J. Thyssen; J. van Stralen; M. López Vidal; S. Villaume; O. Visser; L. K. Sørensen; T. Winther; S. Yamamoto; X. Yuan, Feb. 2026, ［Internationally co-authored］
• Excluding Hypothetical Light Boson Interpretation of Yb King Plot Nonlinearity with the ${}^1S_0 \leftrightarrow {}^3P_2$ Isotope Shift Measurement
  Taiki Ishiyama; Koki Ono; Reiji Asano; Hokuto Kawase; Tetsushi Takano; Ayaki Sunaga; Yasuhiro Yamamoto; Minoru Tanaka; Yoshiro Takahashi, arXiv:2601.08487, 13 Jan. 2026
  We present precision spectroscopy and isotope shift measurement of the ${}^1S_0 \leftrightarrow {}^3P_2$ clock transition in neutral ytterbium ($\mathrm{Yb}$) atoms. By revealing a magic wavelength at $905.4(2)$ nm, we successfully achieve the atomic spectrum narrower than $100$ Hz. The interleaved clock operation between isotopes allows us to determine isotope shifts of four bosonic isotope pairs at Hz-level uncertainties, which is combined with those of other four ultra-narrow transitions in $\mathrm{Yb}$ and $\mathrm{Yb}^+$ to construct the King plot. Importantly, the new isotope shift data reported in this work is a key to exclude the possibility of attributing the observed nonlinearity of the three-dimensional King plot solely to the new physics, while the previous works rely on the other terrestrial bound set by the neutron scattering and $(g-2)_e$ measurements. This work paves the way for the effective use of precision isotope shift data in the King plot analysis and stimulates further measurements in $\mathrm{Yb}$ and other elements.
• New physics searches with precision spectroscopy of ultracold ytterbium
  Koki Ono; Taiki Ishiyama; Reiji Asano; Tetsushi Takano; Naoya Ozawa; Yushiro Nishikawa; Ayaki Sunaga; Yasuhiro Yamamoto; Minoru Tanaka; Yoshiro Takahashi, Technical Meeting on Electronic Circuits, 12 Sep. 2025, [Domestic magazines]
• イッテルビウム原子の精密分光による新物理探索
  高野 哲至; 小野 滉貴; 石山 泰樹; 砂賀 彩光; 山本 康裕; 田中 実; 高橋 義朗, レーザー研究, 51, 8, 511, 516, Aug. 2023, [Peer-reviewed]
  Japanese, Introduction other
• Electric dipole moments and the search for new physics
  Ricardo Alarcon; Jim Alexander; Vassilis Anastassopoulos; Takatoshi Aoki; Rick Baartman; Stefan Baeßler; Larry Bartoszek; Douglas H. Beck; Franco Bedeschi; Robert Berger; Martin Berz; Tanmoy Bhattacharya; Michael Blaskiewicz; Thomas Blum; Themis Bowcock; Kevin Brown; Dmitry Budker; Sergey Burdin; Brendan C. Casey; Gianluigi Casse; Giovanni Cantatore; Lan Cheng; Timothy Chupp; Vince Cianciolo; Vincenzo Cirigliano; Steven M. Clayton; Chris Crawford; B. P. Das; Hooman Davoudiasl; Jordy de Vries; David DeMille; Dmitri Denisov; Milind V. Diwan; John M. Doyle; Jonathan Engel; George Fanourakis; Renee Fatemi; Bradley W. Filippone; Nadia Fomin; Wolfram Fischer; Antonios Gardikiotis; R. F. Garcia Ruiz; Claudio Gatti; James Gooding; Peter Graham; Frederick Gray; W. Clark Griffith; Selcuk Haciomeroglu; Gerald Gwinner; Steven Hoekstra; Georg H. Hoffstaetter; Haixin Huang; Nicholas R. Hutzler; Marco Incagli; Takeyasu M. Ito; Taku Izubuchi; Andrew M. Jayich; Hoyong Jeong; David Kaplan; Marin Karuza; David Kawall; On Kim; Ivan Koop; Valeri Lebedev; Jonathan Lee; Soohyung Lee; Kent K. H. Leung; Chen-Yu Liu; Joshua Long; Alberto Lusiani; William J. Marciano; Marios Maroudas; Andrei Matlashov; Nobuyuki Matsumoto; Richard Mawhorter; Francois Meot; Emanuele Mereghetti; James P. Miller; William M. Morse; James Mott; Zhanibek Omarov; Chris O'Shaughnessy; Cenap Ozben; SeongTae Park; Robert W. Pattie Jr.; Alexander N. Petrov; Giovanni Maria Piacentino; Bradley R. Plaster; Boris Podobedov; Matthew Poelker; Dinko Pocanic; V. S. Prasannaa; Joe Price; Michael J. Ramsey-Musolf; Deepak Raparia; Surjeet Rajendran; Matthew Reece; Austin Reid; Sergio Rescia; Adam Ritz; B. Lee Roberts; Marianna S. Safronova; Yasuhiro Sakemi; Andrea Shindler; Yannis K. Semertzidis; Alexander Silenko; Jaideep T. Singh; Leonid V. Skripnikov; Amarjit Soni; Edward Stephenson; Riad Suleiman; Ayaki Sunaga; Michael Syphers; Sergey Syritsyn; M. R. Tarbutt; Pia Thoerngren; Rob G. E. Timmermans; Volodya Tishchenko; Anatoly V. Titov; Nikolaos Tsoupas; Spyros Tzamarias; Alessandro Variola; Graziano Venanzoni; Eva Vilella; Joost Vossebeld; Peter Winter; Eunil Won; Anatoli Zelenski; Yan Zhou; Konstantin Zioutas, arXiv:2203.08103, 15 Mar. 2022, ［Internationally co-authored］
  Static electric dipole moments of nondegenerate systems probe mass scales for
  physics beyond the Standard Model well beyond those reached directly at high
  energy colliders. Discrimination between different physics models, however,
  requires complementary searches in atomic-molecular-and-optical, nuclear and
  particle physics. In this report, we discuss the current status and prospects
  in the near future for a compelling suite of such experiments, along with
  developments needed in the encompassing theoretical framework.
• Isotope separation by DC18C6 crown-ether for neutrinoless double beta decay of ⁴⁸Ca
  A Rittirong; T Yoshimoto; R Hazama; T Kishimoto; T Fujii; Y Sakuma; S Fukutani; Y Shibahara; A Sunaga, Journal of Physics: Conference Series, 2147, 1, 012015, 012015, 01 Jan. 2022
  Abstract
  
  The isotope separation via liquid-liquid extraction (LLE) using crown-ether (DC18C6) was carried out in order to demonstrate the feasibility of calcium isotope enrichment, which aimed to find a cost-effective way to enrich calcium-48 (⁴⁸Ca) for the study of neutrinoless double beta decay (0vββ) in the CANDLES project. The LLE results revealed that the extraction was solvent dependent in the presence of HCl and the distribution coefficient (D) increased approximately threefold (0.0546±0.0012) with 12 M HCl solvent under a 3.9 M CaCl₂ (aq) (30% w/w) system. Furthermore, the HCl solvent maintained the calcium content attached to the crown-ether at lower feed concentrations. The reaction cell ICP-MS (Agilent 7900) with an additional H2 gas was used to analyze the isotopic composition. The single-stage separation factor of organic phase was found to be 0.992±0.003, 0.994±0.003, 0.996±0.004 for ⁴⁸Ca/⁴²Ca, ⁴⁸Ca/⁴³Ca, and ⁴⁸Ca/⁴⁴Ca, respectively in the extracted organic phase of 3.3 M CaCl₂ (aq) (30% w/w) system. The obtained results were comparable with the HCl solvent system. As a result, without the addition of an acidity reagent, the production of the enriched ⁴⁸Ca isotope via LLE was highly feasible. To improve the mass production of enriched ⁴⁸Ca, filter separation was applied in order to shorten the time required and to study various volumes of the extraction system. The results indicated that the extraction efficiency of filter LLE was comparable to conventional LLE. Filter LLE resulted in more than threefold reduction in time required (approximately 10 minutes for a complete single-stage separation) in comparison with a conventional LLE, consequently implying great potential in the enrichment and mass production via filter LLE., IOP Publishing

• 計算化学（第3版）
  砂賀彩光, 第9章（相対論的量子化学）
  フランク・ジェンセン, 森北出版, Feb. 2023, [Joint translation]

• 〔Major achievements〕Vibrational states and transition intensities based on variational vibrational theory
  Ayaki Sunaga
  41st Symposium on Chemical Kinetics and Dynamics, 03 Jun. 2026, English, Poster presentation
  02 Jun. 2026 - 04 Jun. 2026, Sapporo, [International presentation]
• 〔Major achievements〕変分的振動理論に基づくメタノールの振動状態と遷移強度
  Ayaki Sunaga
  第 28 回 理論化学討論会, 18 May 2026, Japanese, Oral presentation
  18 May 2026 - 20 May 2026, 岡山, [Domestic Conference]
• 〔Major achievements〕Variational vibrational theory with spectroscopic accuracy and its application to methanol
  Ayaki Sunaga
  第四回冷却分子・精密分光シンポジウム, 30 Aug. 2025, Japanese, Invited oral presentation
  29 Aug. 2025 - 30 Aug. 2025, Tokyo, Japan, [Invited], [Domestic Conference]
• 〔Major achievements〕Spectroscopic Quality and Variational Vibrational States of Methanol and Enhancement of Parity-Violating Shift in Substituted Methanols
  Ayaki Sunaga; Edit Mátyus
  29th Colloquium on High-Resolution Molecular Spectroscopy, 25 Aug. 2025, English, Oral presentation
  24 Aug. 2025 - 30 Aug. 2025, Köln, Germany, Contributed Talk, [International presentation], ［Internationally co-authored］
• 〔Major achievements〕Variational Vibrational States of Methanol (12D)
  Ayaki Sunaga; Edit Mátyus
  13th Triennial Congress of the World Association of Theoretical and Computational Chemists, 26 Jun. 2025, English, Invited oral presentation
  22 Jun. 2025 - 27 Jun. 2025, Oslo, Norway, Invited Communications (Contributed Talk), [International presentation], ［Internationally co-authored］
• Fermi-type nuclear model
  Ayaki Sunaga
  28th DIRAC working Group Meeting, 04 Jun. 2025, English, Oral presentation
  03 Jun. 2025 - 06 Jun. 2025
• 分子の大振幅振動に起因するパリティ非保存効果の増幅現象
  砂賀彩光
  第80回日本物理学会春季大会, 19 Mar. 2025, Japanese, Oral presentation
  18 Mar. 2025 - 21 Mar. 2025
• Variational vibrational states of methanol and the development of a new potential energy surface
  Ayaki Sunaga; Gustavo Avila; Tibor Győri; Viktor Tajti; Gábor Czakó; Edit Mátyus
  Anyag- és Molekulaszerkezeti Munkabizottsága (AMMB) ülés, 23 Nov. 2024, English, Oral presentation
  22 Nov. 2024 - 23 Nov. 2024, Mátrafüred, Hungary, [International presentation], ［Internationally co-authored］
• 原子・分子を用いた標準模型を超えた新物理探索〜相対論的電子状態理論の視点から〜
  Ayaki Sunaga
  研究室セミナー（理化学研究所 酒見研究室）, 25 Sep. 2024, Japanese, Invited oral presentation
  [Invited]
• Towards a path following GF method and an application to methanol in 12D
  Ayaki Sunaga; Gustavo Avila; Edit Mátyus
  第18回分子科学討論会, 21 Sep. 2024, Japanese, Oral presentation
  18 Sep. 2024 - 21 Sep. 2024
• Full-Dimensional (12D) Variational Vibrational States of Methanol and 1D Computation of Chiral Methanol Compounds for Parity-Violation Search
  Ayaki Sunaga; Gustavo Avila; Edit Mátyus
  77th International Symposium on Molecular Spectroscopy, 19 Jun. 2024, English, Oral presentation
  17 Jun. 2024 - 21 Jun. 2024, Illinois (US), [International presentation], ［Internationally co-authored］
• Benchmark 12D vibrational computation of methanol and search for enhanced parity violation effects in substituted methanol compounds
  Ayaki Sunaga; Gustavo Avila; Edit Mátyus
  AMMB minikonferencia, 22 Apr. 2024, Oral presentation
  22 Apr. 2024 - 22 Apr. 2024
• Benchmark 12D vibrational computation of methanol and search for enhanced parity violation effects in substituted methanol compounds
  Ayaki Sunaga; Gustavo Avila; Edit Mátyus
  AMOC2024: Atoms, Molecules and Clusters in Motion Conference, 17 Apr. 2024, Poster presentation
  15 Apr. 2024 - 18 Apr. 2024
• 4-component relativistic Hamiltonian with effective QED potentials for molecular calculations
  A. Sunaga; M. Salman; T. Saue
  The 28th Colloquium on High Resolution Molecular Spectroscopy, Dijon, France, 28 Aug. 2023, English, Oral presentation
  28 Aug. 2023 - 01 Sep. 2023
• 4-component relativistic Hamiltonian with effective QED potentials for molecular calculations
  Ayaki Sunaga; Maen Salman; Trond Saue
  17th International Congress of Quantum Chemistry, 30 Jun. 2023, English, Poster presentation
  26 Jun. 2023 - 01 Jul. 2023
• 相対論的励起状態計算に基づく核磁気四重極モーメントの探索実験の提案
  砂賀 彩光; ブータ アマール; 高橋 唯基; 高橋 義朗
  第25回理論化学討論会, 17 May 2023, Japanese, Oral presentation
  16 May 2023 - 19 May 2023
• Relativistic calculations of enhancement factors for nuclear magnetic quadrupole moment in Yb atom
  Ayaki Sunaga; Amar Vutha; Yuiki Takahashi; Yoshiro Takahashi
  第78回日本物理学会春季大会, 23 Mar. 2023, Japanese, Oral presentation
  22 Mar. 2023 - 25 Mar. 2023
• 相対論的多電子理論が切り拓く新物理探索への道
  Ayaki Sunaga
  量子宇宙研究コアセミナー（岡山大学 異分野基礎科学研究所）, 09 Mar. 2023, Japanese, Invited oral presentation
  [Invited]
• 化学における量子電磁力学効果と分子を用いたCP 対称性破れの探索
  Ayaki Sunaga
  第18回京都大学福井謙一記念研究センターシンポジウム, 10 Feb. 2023, Japanese, Invited oral presentation
  10 Feb. 2023 - 10 Feb. 2023, [Invited]
• ダークマター探索を目指した同位体シフトの相対論計算
  砂賀 彩光; 小野 滉貴; 石山 泰樹; 高野 哲至; 高須 洋介; 田中 実; 高橋 義朗
  The 14th International Workshop on Fundamental Physics Using Atoms (FPUA2022), 24 Nov. 2022
  24 Nov. 2022 - 25 Nov. 2022
• 相対論的結合クラスター法：理論と重原子分子への応用
  Ayaki Sunaga
  核多体セミナー（京都大学 萩野研究室）, 18 Nov. 2022, Japanese, Invited oral presentation
  [Invited]
• 相対論的多体理論が先導する同位体シフトにおける新物理
  砂賀 彩光; 小野 滉貴; 田中 実; 高橋 義朗
  第1回 新方式精密計測による物理・工学的変革を目指す回路技術調査専門委員会, 30 Jun. 2022, Oral presentation
  30 Jun. 2022 - 30 Jun. 2022, [Invited]
• 同位体シフトにおける標準模型を超えた新物理：相対論に基づく精密計算と解析
  砂賀 彩光; 小野 滉貴; 田中 実; 高橋 義朗
  第24回理論化学討論会, 19 May 2022, Japanese, Oral presentation
  17 May 2022 - 20 May 2022
• 相対論的多体理論を用いた同位体シフトにおける新物理の探索
  砂賀彩光; 小野滉貴; 田中実; 高橋義朗
  第77回日本物理学会春季大会, 17 Mar. 2022, Oral presentation
  15 Mar. 2022 - 19 Mar. 2022
• The linearity of UO2(2+) and UN2 revisited; structure and chemical bond based on a relativistic study
  砂賀彩光
  専門研究会「アクチノイドの物性化学とその応用」, 04 Mar. 2022, Japanese, Oral presentation
  03 Mar. 2022 - 04 Mar. 2022
• The structures of UO2(2+) and UN2 revisited: the stability and chemical bond based on relativistic calculations
  Ayaki Sunaga
  Group seminar (Andre Gomes group; Université de Lille), 12 Feb. 2022, English, Invited oral presentation
  12 Feb. 2022 - 12 Feb. 2022, [Invited]
• 相対論的量⼦化学計算に基づくUO2(2+), UN2の化学結合解析
  砂賀彩光
  ⼤洗・アルファ合同研究会, 01 Oct. 2021
  29 Sep. 2021 - 01 Oct. 2021
• Quantum electrodynamic effects for molecular properties of heavy element systems: development of an accurate relativistic molecular theory and its application
  Ayaki Sunaga; Maen Salman; Trond Saue
  The 15th Annual meeting of Japan Society for Molecular Science 2021, 21 Sep. 2021, Japanese, Oral presentation
  18 Sep. 2021 - 21 Sep. 2021
• Parity-violating energy difference in chiral molecules enhanced by electronic excitation
  Ayaki Sunaga
  Quantum Science Symposium, 17th International Conference of Computational Methods in Sciences and Engineering (ICCMSE) 2021 (Video Conference (Streaming)), Sep. 2021, English, Invited oral presentation
  Sep. 2021 - Sep. 2021, [Invited]
• 相対論的EOM-CC法を用いた鏡像異性体間のエネルギー差の計算: 電子励起による特異的増大
  黒田 直也; 於保匠; 砂賀彩光; 瀬波大土
  第15回分子科学討論会, Sep. 2021, Japanese, Oral presentation
• パリティの破れに起因する鏡像異性体間エネルギー差の電子励起による増大
  黒田 直也; 於保匠; 砂賀彩光; 瀬波大土
  日本物理学会2021年秋季大会, Sep. 2021, Japanese
• Understanding of T, P violating interaction parameters in polyatomic polar molecules
  Naoya Kuroda; Ayaki Sunaga; Masato Senami
  Quantum Science Symposium, 17th International Conference of Computational Methods in Sciences and Engineering (ICCMSE) 2021 (Video Conference (Streaming)), Sep. 2021, English, Oral presentation
• Many-body calculation for the electron EDM searches: mechanism of enhancement for effective electric field and many-body theory including QED effects
  Ayaki Sunaga
  Fundamental Physics Using Atoms (FPUA 2021), 04 Aug. 2021, English, Oral presentation
  04 Aug. 2021 - 05 Aug. 2021
• Isotope Separation of Calcium and Lithium by Chemical Exchange Method using DC18C6 Crown-Ether
  Anawat Rittirong; Pannipa Noithong; Takaaki Yoshimoto; Ryuta Hazama; Tadafumi Kishimoto; Toshiyuki Fujii; Yoichi Sakuma; Satoshi Fukutani; Yuji Shibahara; Ayaki Sunaga
  18th Symposium on Host-Guest and Supramolecular Chemistry, 26 Jun. 2021, Poster presentation
  26 Jun. 2021 - 27 Jun. 2021
• Effective QED potentials for relativistic correlated molecular calculations including QED effects
  Ayaki Sunaga
  24th DIRAC working Group Meeting, virtual via ZOOM, 26 May 2021, English, Oral presentation
  25 May 2021 - 28 May 2021
• Relativistic molecular calculations of spectroscopic constants and chemical bondings including QED effects
  Ayaki Sunaga; Maen Salman; Trond Saue
  Annual Meeting of Japan Society of Theoretical Chemistry (2021）, 14 May 2021, Japanese, Oral presentation
  13 May 2021 - 15 May 2021
• Theoretical study of the linearity of uranyl molecule based on relativistic correlation method
  Ayaki Sunaga
  Topical meeting on Condensed-matter Chemistry on Actinides (Kumatori meeting), 10 Feb. 2021, Poster presentation
  10 Feb. 2021 - 10 Feb. 2021
• Theoretical study towards the detection of P, T violating interactions: analysis of enhancement factors and correction of QED effects
  Ayaki Sunaga
  5th Committee of circuit for the scientific technical revolution based on the precise measurement, 17 Nov. 2020, English, Nominated symposium
  17 Nov. 2020 - 17 Nov. 2020, [Invited]
• Relativistic study on the linearity of uranyl molecule
  Ayaki Sunaga
  GIMRT Joint International Symposium on Radiation Effects in Materials and Actinide Science, 01 Oct. 2020, English, Poster presentation
  30 Sep. 2020 - 03 Oct. 2020
• Relativistic many-body calculations on molecules including effective QED potentials
  Ayaki Sunaga
  Fundamental Sciences & Quantum Technologies using Atomic Systems, 01 Oct. 2020, English, Oral presentation
  28 Sep. 2020 - 01 Oct. 2020
• Relativistic correlated calculations with effective QED potentials
  Ayaki Sunaga
  23nd DIRAC working Group Meeting, virtual via ZOOM, 04 Jun. 2020, English
• Using effective QED potentials in molecular calculations
  Ayaki Sunaga; Trond Saue
  Computation and Understanding in Quantum Molecular Science, 04 Sep. 2019
• Using effective QED potentials in molecular calculations
  Ayaki Sunaga; Trond Saue
  10th Triennial Congress of the International Society for Theoretical Chemical Physics, 15 Jul. 2019
• Enhancement Factors of Parity- and Time-Reversal-Violating Effects for Monofluorides
  Ayaki Sunaga
  International Summit on Optics, Photonics and Laser Technologies, 04 Jun. 2019, English, Invited oral presentation
  SAN FRANCISCO, [Invited], [International presentation]
• Molecular calculations with effective QED potentials
  Ayaki Sunaga; Trond Saue
  22nd DIRAC Working Group Meeting, 28 May 2019
• Relativistic study of parity and time reversal symmetry-violating interaction using atoms and molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  16th International Congress of Quantum Chemistry, 20 Jun. 2018
• Analysis of enhancement factors of electron EDM and scalarpseudoscalar interaction for atoms and molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  7th JCS (Japan-Czech-Slovak) Symposium, 21 May 2018
• Analysis of enhancement factors of electron EDM and scalar-pseudoscalar interaction for atoms and molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  10th International Workshop on Fundamental Physics Using Atoms 2018, 10 Jan. 2018
• Analysis of Effective Electric Fields of Heavy Molecules for Electron Electric-Dipole-Moment Searches
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  Theoretical Design of Materials with Innovative Functions Based on Element Strategy and Relativistic Electronic Theory, 08 Dec. 2017
• Anomalous increase of relativistic effect for hyperfine coupling constant of outer orbitals
  Ayaki Sunaga; Minori Abe; Masahiko Hada
  12th International Conference on Relativistic Effects in Heavy-Element Chemistry and Physics, 04 Sep. 2017
• Analysis of hyperfine structure in Dirac theory: anomalous increase of relativistic contraction of outer orbitals
  Ayaki Sunaga; Minori Abe; Masahiko Hada
  11th Triennial Congress of the World Association of Theoretical and Computational Chemists, 31 Aug. 2017
• 4成分相対論における超微細結合定数の定式化に関する考察
  砂賀彩光; 阿部穣里; 波田雅彦
  日本コンピュータ化学会2017春季年会, 09 Jun. 2017
• 4 成分相対論にも適用可能な超微細結合定数の演算子に関する検討
  砂賀彩光; 阿部穣里; 波田雅彦
  第20回 理論化学討論会, 16 May 2017
• Analysis of large effective electric fields of weakly polar molecules for eEDM searches
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  9th International Workshop on Fundamental Physics Using Atoms 2017, 10 Jan. 2017
• 電子EDM探査に向けた重原子分子の電子状態解析と有効電場計算
  砂賀彩光; 阿部穣里; Bhanu Pratap Das; 波田雅彦
  第17回 大つくば物理化学セミナー,, 27 Nov. 2016
• Dirac理論に基づく超微細結合定数の解析－外殻軌道における相対論効果の増幅現象－
  砂賀彩光; 阿部穣里; 波田 雅彦
  第11回 分子科学討論会, 27 Nov. 2016
• 電子EDM探査を目指した2原子分子内の有効電場の方向に関する考察
  砂賀彩光; 阿部穣里; Bhanu Pratap Das; 波田 雅彦
  第10回 分子科学討論会, 15 Sep. 2016
• Analysis of electric effective fields of heavy molecule for search of the electron EDM
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  25th International Conference on Atomic Physics, 25 Jun. 2016
• 電子EDM探査のための有効電場解析: XH分子とXF分子の比較
  砂賀彩光; 阿部穣里; B. P. Das; 波田雅彦
  日本コンピュータ化学会2016春季年会, 02 Jun. 2016
• 電子 EDM 探査のための相対論的量子化学計算による有効電場の解析
  砂賀彩光; 阿部穣里; Bhanu Pratap Das; 波田雅彦
  第19回 理論化学討論会, 25 May 2016
• Quantum-Chemical calculations of the scalar-pseudoscalar interaction in heteronuclear diatomic molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  Symposium: New Generation Quantum Theory -Particle Physics, Cosmology, and Chemistry-, 08 Mar. 2016
• Quantum-chemical calculations of the scalar-pseudoscalar interaction in heteronuclear diatomic molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  The Global Human Resource Program Bridging across Physics and Chemistry, 30 Jan. 2016, English, Poster presentation
• Quantum-Chemical calculations of the scalar-pseudoscalar interaction in heteronuclear diatomic molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  Pacifichem 2015, 17 Dec. 2015, English, Poster presentation
• Why HgF has larger Ws than other XF molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  8th International Workshop on Fundamental Physics Using Atoms 2015 - Towards better understanding of our matter universe -, 30 Nov. 2015, Japanese, Oral presentation
• 異核2原子分子におけるscalar-pseudoscalar相互作用の量子化学的研究
  砂賀彩光; 阿部穣里; Bhanu Pratap Das; 波田 雅彦
  第9回 分子科学討論会, 17 Sep. 2015
• Quantum-Chemical calculations of the scalar-pseudoscalar interaction in heteronuclear diatomic molecules
  Ayaki Sunaga; Minori Abe; Bhanu Pratap Das; Masahiko Hada
  Exploring Fundamental Physics using Atomic Systems, 07 May 2015, English, Poster presentation
  [International presentation]

• Dec. 2021 - Present
  The Physical Society of Japan
• Feb. 2021 - Present
  Japan Society of Theoretical Chemistry
• Sep. 2020 - Present
  Japan Society of Coordination Chemistry
• Apr. 2017 - Present
  THE SOCIETY OF ELECTRON SPIN SCIENCE AND TECHNOLOGY
• Mar. 2016 - Present
  SOCIETY OF COMPUTER CHEMISTRY, JAPAN
• Oct. 2015 - Present
  The atomic collision society of Japan
• Oct. 2015 - Present
  JAPAN SOCIETY FOR MOLECULAR SCIENCE

• Quantum dynamics for systems with multiple internal rotations toward the search for new physics and chemistry in the universe
  STARTING_25
  Jan. 2026 - Dec. 2027
  Declining due to returning to Japan
  National Research, Development and Innovation Office (Hungary), Eötvös Loránd University, Principal investigator, Competitive research funding, 153122
• Quantum dynamics of floppy systems beyond Coulomb interactions: magnetic and parity-violating effects (QDMAP)
  Marie Skłodowska-Curie Actions Individual Fellowship
  Sep. 2023 - Aug. 2025
  Ayaki Sunaga
  European Union, Horizon, Eötvös Loránd University, 101105452
• Relativistic effects on the ligand field of metal complexes: a fundamental theory of heavy element chemistry
  Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists
  Apr. 2021 - Mar. 2024
  Ayaki Sunaga
  金属錯体の配位子場分裂は現象論としてよく知られているが、重金属錯体を理論的に扱う場合は、相対論効果を考慮して計算を行う必要がある。相対論効果のうち、スカラー相対論効果は、縮退したd軌道の分裂形式（例えば、正八面体型錯体であれば2:3）に影響を与えないが、スピン-軌道相互作用効果（SO効果）によるd軌道の分裂を考慮した場合は、分裂形式が変化する可能性がある。また対称性がよく、縮退した分子軌道をもつ系の理論計算は、多配置性を考慮した電子相関法を用いた計算を行う必要がある。
  本研究では、（1）SO効果と（2）多配置性の両方を考慮した相対論的配置間相互作用（CI）法を用いて対称性が高い重金属錯体を計算し、配位子場分裂におけるSO効果の影響を明らかにすることを目的とする。また、ヤーン・テラー歪み（静的ヤーン・テラー効果）におけるSO効果の影響も議論する。当研究の計算には、相対論計算専用のプログラムであるDIRACを用いる。相対論効果はeXact 2-Component（X2C）ハミルトニアンを用いることで考慮する。X2C法は、化学で必要な相対論効果を十分に考慮できる2成分相対論法である。2電子間のSO効果はatomic mean-field spin-orbit integral（AMFI）法を用いて考慮する。
  計算対象としては、第六周期の遷移金属錯体に加え、第七周期元素（超重元素）を含んだ錯体と比較する。これにより周期表を縦断した重金属錯体の理解を可能とする。SO分裂を考慮した配位子場分裂の分子軌道ダイアグラムを作成し、将来的に錯体化学の教科書に記載されるような、重元素化学の理論的基盤を構築する。
  Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Kyoto University, 21K14643
• Analysis of chemical bonding in actinide compounds based on relativistic quantum chemistry
  Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity start-up
  Sep. 2020 - Mar. 2022
  Sunaga Ayaki
  Since actinide compounds are heavy systems, it is required to perform calculations that incorporate relativistic effects such as spin-orbit (S0) interactions. In this study, we developed a program to carry out the analysis of chemical bonds with reliable accuracy, taking SO effects into account. Using this program, we analyzed the chemical bonds of UO2(2+) and UN2 molecules and showed that these molecules form a triple bond between U-O and U-N even in the bent structure. Our accurate calculations at the relativistic CCSD(T) level indicate that the bent conformations of UO2(2+) and UN2 molecules are relatively stable compared to the predictions using the less accurate Hartree-Fock method reported in previous studies.
  Japan Society for the Promotion of Science, Grant-in-Aid for Research Activity start-up, Kyoto University, 20K22553
• Development of high-precision electronic structure theory including QED effect: Exploring new physics beyond the standard model
  Grant-in-Aid for JSPS Fellows
  Apr. 2017 - Mar. 2020
  Ayaki Sunaga
  Japan Society for the Promotion of Science (JSPS), Principal investigator, Competitive research funding
• Development of high-precision electronic structure theory including QED effect: Exploring new physics beyond the standard model
  Overseas Challenge Program for Young Researchers
  Apr. 2018 - Mar. 2019
  Ayaki Sunaga
  Japan Society for the Promotion of Science (JSPS), Principal investigator, Competitive research funding

• Science day
  22 May 2025 - 22 May 2025
  Appearance
  Eötvös Loránd University Institute of Chemistry
  Science day
  Poster presentation at an event to present research results of the Institute of Chemistry, Eötvös Loránd University, to companies and undergraduates (title: 12D vibrational computation of methanol and search for enhanced parity violation effects in substituted methanol compounds).
• 56th summerschool in molecular science (organizer)
  Oct. 2015 - Sep. 2016
  Planner, Organizing member
  分子科学若手の会 第56回分子科学若手の会夏の学校

• 宇宙の謎「暗黒物質」検出へ、世界一正確な時計活用 京大が基礎技術
  Mar. 2026
  Other than myself
  日本経済新聞
  [Paper]
• 京大，内殻電子が励起する時計遷移を初観測
  17 Apr. 2023
  OPTRONICS ONLINE
  [Internet]
• 京大、新たな光格子時計候補「イッテルビウム」の時計遷移を直接観測
  17 Apr. 2023
  マイナビニュース TECH+
  [Internet]
• 【注目プレスリリース】内殻電子が励起する時計遷移の初観測に成功―新奇な光格子時計を用いた超高感度な新物理探索へ― / 京都大学
  17 Apr. 2023
  日本の研究.comニュース
  [Internet]
• 内殻電子が励起する時計遷移の初観測に成功～新奇な光格子時計を用いた超高感度な新物理探索へ～
  17 Apr. 2023
  Tii技術情報
  [Internet]