title: Plasmon interpretation of 25 cm-1 mode in DNA.
abstract: An extension of the effective field approach for the normal mode dynamics of dissolved DNA polymers has been applied to study the vibrational modes of DNA-hydration sheath-counterion system, to include the effect of site bound counterions on the system dynamics. An alternative interpretation has been suggested for a 25 cm-1 mode recently observed in DNA samples and interpreted earlier as an interhelical mode. Analysing the eigenvectors this mode is found to possess a large electric dipole moment with longitudinal collective oscillations of the system. These characteristics identify this mode as a collective plasmon mode. Possible physical reasons for the existence of this character have been presented.
authors.affiliation: Department of Physics, Purdue University, West Lafayette, IN 47907.
authors.forename: V K
authors.initials: VK
authors.lastname: Saxena
authors.forename: L L
authors.initials: LL
authors.lastname: Van Zandt
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D009038:Motion; D011067:Poly dA-dT / Q000737:chemistry; D012964:Sodium; D014732:Vibration; D014867:Water
chemical_list: D014867:Water; D011067:Poly dA-dT; D004247:DNA; D012964:Sodium