Prof. Nakai will give an invited talk at 19th Japan-Korea Symposium on Molecular Science.

Date: July 22 – July 24, 2026

Place: The University of Tokyo

Contents

〇Hiromi Nakai,“Theoretical Study on Molecular Structures at the  S0/S1 Minimum Energy Conical Intersection”.

Prof. Nakai will give an invited talk at the International Conference on Computational and Mathematical Methods in Science and Engineering (CMMSE).

Date: July 2 – July 9, 2026

Place: Barceló Costa Ballena Golf & SPA (Cádiz, Spain)

Contents

• 〇Hiromi Nakai, “Low-Rank Representations of Two-Particle Cumulants for Divide-and-Conquer Electronic Structure Theory”.

Prof. Nakai will give an invited talk and our group member will give 4 poster presentations at 18th International Congress on Quantum Chemistry (ICQC2026).

Date: May 31 – June 5, 2026
Place: UC Berkeley, USA

Contents

• 〇Hiromi Nakai, “Density-matrix-based fragmentation approach for treating nonlocal static correlation”(Invited Talk).
• 〇Chinami Takashima, Hiromi Nakai, “Reduced-density-matrix-based divide-and-conquer method unifying energy- and density-matrix-based approaches for static correlation”(Poster).
• 〇Ryusei Nishimura, Takeshi Yoshikawa, Ken Sakata, Hiromi Nakai, “Excited-state geometry optimization using divide-and-conquer-based non-local excited-state calculation method”(Poster).
• 〇Shugo Shibuta, Rei Oshima, Hiromi Nakai, “Linear-scaling divide-and-conquer (DC) approach for the antisymmetrized product of strongly orthogonal geminals (APSG) method”(Poster).
• 〇Rei Oshima, Airi Kawasaki, Naoki Nakatani, Hiromi Nakai, “Givens rotation based framework for orbital optimization in Hartree–Fock and antisymmetric product of geminals (APG) theories”(Poster).

Prof. Nakai will give lectures and our group members will give 4 poster presentations at The 2025 International Chemical Congress of Pacific Basin Societies (Pacifichem)

Date: December 15-20, 2025
Place: Honolulu, Hawaii

Contents

• 〇Hiromi Nakai, Mikito Fujinami, “Exploring oxaza[7]dehydrohelicene derivatives with strong circularly polarized luminescence using machine learning and time-dependent density functional theory”(Invited Talk).
• 〇Hiromi Nakai,“Overcoming limitations of fragmentation methods for non-local interactions”(Invited Talk)
• 〇Chinami takashima, Hiromi Nakai, “Electron correlation method based on two-particle reduced density matrix toward large-scale systems”(Poster)
• 〇Rei Oshima, Hiromi Nakai, “Efficient SCF convergence method using Givens rotation and error back propagation”(Poster)
• 〇Ryusei Nishimura, Takeshi Yoshikawa, Ken Sakata, Hiromi Nakai, “Geometry Optimization of Delocalized Excited States via the Divide-and-Conquer Approach”(Poster)
• 〇Miyu Onishi, Ayako Nakata, Hiromi Nakai, “Theoretical investigation of supported metal nanoparticle via first-principles calculation”(Poster)

Mr. Ohsima (D2) will give oral presentation at The Annual Meeting of Taiwan Theoretical and Computational Molecular Sciences Association(T2C0MSA).2025

Date: Date: August 21-22, 2025
Place: College of Science, National Sun-Yat sen University, Taiwan

Content

• 〇Rei Oshima, Hiromi Nakai，”Direct minimization method for SCF solution combining Givens rotation and error backpropagation”(Oral presentation).

The 38th Quantum Chemistry Seminar will be held at Waseda University.

Prof. Andrés Reyes will give a lecture.

Date and Time: Tuesday, August 5, 2025, 16:00-17:40
Venue: Room 904, Building 55S, Nishiwaseda Campus, Waseda University

Presentation Title:“My name is Bond, positron bond”

Prof. Nakai will give an invited talk and Dr. Takashima will give poster presentation at 13th Triennial Congress of the World Association of Theoretical and Computational Chemists (WATOC 2025).

Date: Date: June 22-27, 2025
Place: Oslo, Norway

Contents

• 〇Hiromi Nakai, ”Breaking Barriers in Fragmentation Methods for Long-Range Interactions”(Invited Talk).
• 〇Chinami Takashima, Hiromi Nakai, ”Parallel implementation of two-electron integral transformation in infinite-order two-component theory”(Poster).