title: Quadrupolar NMR Spin Relaxation Calculated Using Ab Initio Molecular Dynamics: Group 1 and Group 17 Ions in Aqueous Solution.
abstract: Electric field gradient (EFG) fluctuations for the monoatomic ions (7)Li(+), (23)Na(+), (35)Cl(-), (81)Br(-), and (127)I(-) in aqueous solution are studied using Car-Parrinello ab initio molecular dynamics (aiMD) simulations based on density functional theory. EFG calculations are typically performed with 1024 ion-solvent configurations from the aiMD simulation, using the Zeroth Order Regular Approximation (ZORA) relativistic Hamiltonian. Autocorrelation functions for the spherical EFG tensor elements are computed, transformed into the corresponding spectral densities (under the extreme narrowing condition), and subsequently converted into NMR quadrupolar relaxation rates for the ions. The relaxation rates are compared with experimental data. The order of magnitude is correctly predicted by the simulations. The computational protocol is tested in detail for (81)Br(-).
authors.affiliation: Department of Chemistry, University at Buffalo-State University of New York , Buffalo, New York 14260-3000, United States.
authors.forename: Shyam
authors.initials: S
authors.lastname: Badu
authors.affiliation: Institut des Sciences Moléculaires, Université Bordeaux I , 351 Cours de la Libration, 33405 Talence, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Truflandier
authors.affiliation: Department of Chemistry, University at Buffalo-State University of New York , Buffalo, New York 14260-3000, United States.
authors.forename: Jochen
authors.initials: J
authors.lastname: Autschbach