Molecular Dynamics and Hydrogen Bonds in Water.

Fast and Slow Dynamics of Hydrogen Bonds in Liquid Water

We study hydrogen-bond dynamics in liquid water at low temperatures using molecular dynamics simulations. We find that bond lifetime (“fast dynamics”) has Arrhenius temperature dependence. We also calculate the bond correlation function and find that the correlation time (“slow dynamics”) shows power-law behavior. This power-law behavior, as well as the decay of the bond correlations, is consis...

Vibrational dynamics of hydrogen bonds

Motion of Water Molecules and Hydrogen Bonds

The *H N M R spin-lattice relaxation time 7 \ , C1 NQR frequency VQ, and C1 NQR spin-lattice relaxation time 7 \ Q of [ Z n ( H 2 0 ) 6 ] [SnCl6] (zinc hexachlorostannate(IV) hexahydrate) have been measured at temperatures between 77 and 350 K. The NQR spin echo signal with Vq— 15.689 MHz at 77 K showed a positive temperature coefficient attributable to O H C l type H-bonds in the crystal. vQ a...

Halogen bonds as orthogonal molecular interactions to hydrogen bonds.

Halogen bonds (X-bonds) are shown to be geometrically perpendicular to and energetically independent of hydrogen bonds (H-bonds) that share a common carbonyl oxygen acceptor. This orthogonal relationship is accommodated by the in-plane and out-of-plane electronegative potentials of the oxygen, which are differentially populated by H- and X-bonds. Furthermore, the local conformation of a peptide...

Understanding the role of hydrogen bonds in water dynamics and protein stability.

The mechanisms of cold and pressure denaturation of proteins are a matter of debate, but it is commonly accepted that water plays a fundamental role in the process. It has been proposed that the denaturation process is related to an increase of hydrogen bonds among hydration water molecules. Other theories suggest that the causes of denaturation are the density fluctuations of surface water, or...