Evaluation of nucleotide C-Br⋯O-P contacts from ONIOM calculations: Theoretical insight into halogen bonding in nucleic acids

► Halogen bonds buried in nucleic acids were explored by the ONIOM method. ► Analysis of reduced density gradient was carried out on halogen bonds. ► Halogen bonds were visualized by the ELF approach. ► Flexibility of nucleic acid chains is sensitive to the presence of halogen bonds.