Development of positron chemical reaction theory for biomolecules

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05365
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Saitama University
• Principal Investigator: Takayanagi Toshiyuki 埼玉大学, 理工学研究科, 教授 (90354894)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 量子化学 / 量子散乱理論 / 反応動力学

Outline of Final Research Achievements

Positrons, which are antiparticles of electrons, have long been employed in technological applications including material and medical sciences. For example, positron emission tomography (PET) is one of such important applications. However, understanding of detailed atomic-level interactions between positrons and molecules is yet insufficient. The purpose of this study is to understand the detailed interaction between positrons and biomolecules at an atomic level. To achieve this, we have developed the positron-electron correlation-polarization potential model, which is based on density-functional theory. We have also developed a practical method that can directly calculate the annihilation spectrum using vibrational Feshbach resonance widths as a function of positron collision energy.

Free Research Field

理論化学

Academic Significance and Societal Importance of the Research Achievements

我々が新しく開発した密度汎関数法に基づく相関分極ポテンシャル理論を生体分子を含む様々な分子に適用した。その結果、実験で得られている陽電子束縛エネルギーをほぼ定量的に再現することができた。特に極性をもたない分子については、分子の分極率やπ電子と相互作用が重要な役割をしていることを見出した。また、開発した陽電子消滅スペクトルを計算する理論も様々な分子に適用し、実験で得られたスペクトルと一致した結果を得ることができた。