We have provided oral and poster presentations in The 15th annual meeting of Japan Society for Molecular Science 2021, organized by Hokkaido University, on 18-21 September 2021. Study on CH stretching Fermi triad of benzene clusters by IR spectroscopy (Ishihara, oral) Enhanced chiral-recognition of propylene oxide induced by hydrogen bond (Matsumoto, oral) Infrared spectroscopic study on dihydrogen-bonded structures of acetylene-alkylsilane clusters (Hirota, poster)