Water Molecule

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Ludger Inhester - One of the best experts on this subject based on the ideXlab platform.

  • x ray multiphoton ionization dynamics of a Water Molecule irradiated by an x ray free electron laser pulse
    Physical Review A, 2016
    Co-Authors: Ludger Inhester, Kota Hanasaki, Sangkil Son, Robin Santra, Yajiang Hao
    Abstract:

    We present a theoretical investigation of x-ray multiphoton ionization dynamics of polyatomic Molecules, based on the rate equation model and molecular electronic structure calculations. An efficient numerical procedure is developed to calculate photoionization cross sections, Auger rates, and fluorescence rates for all possible electronic multiple-hole configurations of Molecules. We investigate the charge-state distribution of a Water Molecule after interaction with an intense x-ray pulse and discuss its dependence on the fluence and the pulse duration of the x-ray beam. Our results demonstrate that a Water Molecule exposed to an intense x-ray pulse is more ionized than what would be expected within the independent-atom picture.

  • auger spectrum of a Water Molecule after single and double core ionization
    Journal of Chemical Physics, 2012
    Co-Authors: Ludger Inhester, Carl F Burmeister, Gerrit Groenhof, Helmut Grubmuller
    Abstract:

    The high intensity of free electron lasers opens up the possibility to perform single-shot Molecule scattering experiments. However, even for small Molecules, radiation damage induced by absorption of high intense x-ray radiation is not yet fully understood. One of the striking effects which occurs under intense x-ray illumination is the creation of double core ionized Molecules in considerable quantity. To provide insight into this process, we have studied the dynamics of Water Molecules in single and double core ionized states by means of electronic transition rate calculations and ab initio molecular dynamics (MD) simulations. From the MD trajectories, photoionization and Auger transition rates were computed based on electronic continuum wavefunctions obtained by explicit integration of the coupled radial Schrodinger equations. These rates served to solve the master equations for the populations of the relevant electronic states. To account for the nuclear dynamics during the core hole lifetime, the calculated electron emission spectra for different molecular geometries were incoherently accumulated according to the obtained time-dependent populations, thus neglecting possible interference effects between different decay pathways. We find that, in contrast to the single core ionized Water Molecule, the nuclear dynamics for the double core ionized Water Molecule during the core hole lifetime leaves a clear fingerprint in the resulting electron emission spectra. The lifetime of the double core ionized Water was found to be significantly shorter than half of the single core hole lifetime.

  • auger spectrum of a Water Molecule after single and double core ionization by intense x ray radiation
    Biophysical Journal, 2012
    Co-Authors: Ludger Inhester, Gerrit Groenhof, Helmut Grubmuller
    Abstract:

    The high intensity of new x-ray sources such as Free Electron Lasers (FEL) offers the possibility to do single-shot Molecule diffraction experiments. Even for small Molecules, the dynamics induced by the radiation damage in such experiments are not yet fully understood. In particular, double core-ionized Molecules are expected to be created in considerable quantity.We have therefore studied the electronic and nuclear dynamics of Water Molecules in single and double core ionized states by means of electronic transition rates and ab initio molecular dynamics (MD) simulations. From MD trajectories Auger transition rates were computed based on continuum electronic wavefunctions obtained by explicit integration of the coupled radial Schrodinger equations. The calculated spectra for different molecular geometries were accumulated to account for the effects of nuclear dynamics during the core-hole lifetime.In contrast to the single core ionized Water Molecule, we found that dissociation dynamics of double core-ionized Water have strong effect on the resulting electron emission spectra. In addition, we found that the single core hole lifetime is slightly smaller than the value obtained in earlier theoretical works. Finally, we predict that the lifetime of double core ionized states is significantly lower than half of the lifetime of a single core hole.

Helmut Grubmuller - One of the best experts on this subject based on the ideXlab platform.

  • auger spectrum of a Water Molecule after single and double core ionization
    Journal of Chemical Physics, 2012
    Co-Authors: Ludger Inhester, Carl F Burmeister, Gerrit Groenhof, Helmut Grubmuller
    Abstract:

    The high intensity of free electron lasers opens up the possibility to perform single-shot Molecule scattering experiments. However, even for small Molecules, radiation damage induced by absorption of high intense x-ray radiation is not yet fully understood. One of the striking effects which occurs under intense x-ray illumination is the creation of double core ionized Molecules in considerable quantity. To provide insight into this process, we have studied the dynamics of Water Molecules in single and double core ionized states by means of electronic transition rate calculations and ab initio molecular dynamics (MD) simulations. From the MD trajectories, photoionization and Auger transition rates were computed based on electronic continuum wavefunctions obtained by explicit integration of the coupled radial Schrodinger equations. These rates served to solve the master equations for the populations of the relevant electronic states. To account for the nuclear dynamics during the core hole lifetime, the calculated electron emission spectra for different molecular geometries were incoherently accumulated according to the obtained time-dependent populations, thus neglecting possible interference effects between different decay pathways. We find that, in contrast to the single core ionized Water Molecule, the nuclear dynamics for the double core ionized Water Molecule during the core hole lifetime leaves a clear fingerprint in the resulting electron emission spectra. The lifetime of the double core ionized Water was found to be significantly shorter than half of the single core hole lifetime.

  • auger spectrum of a Water Molecule after single and double core ionization by intense x ray radiation
    Biophysical Journal, 2012
    Co-Authors: Ludger Inhester, Gerrit Groenhof, Helmut Grubmuller
    Abstract:

    The high intensity of new x-ray sources such as Free Electron Lasers (FEL) offers the possibility to do single-shot Molecule diffraction experiments. Even for small Molecules, the dynamics induced by the radiation damage in such experiments are not yet fully understood. In particular, double core-ionized Molecules are expected to be created in considerable quantity.We have therefore studied the electronic and nuclear dynamics of Water Molecules in single and double core ionized states by means of electronic transition rates and ab initio molecular dynamics (MD) simulations. From MD trajectories Auger transition rates were computed based on continuum electronic wavefunctions obtained by explicit integration of the coupled radial Schrodinger equations. The calculated spectra for different molecular geometries were accumulated to account for the effects of nuclear dynamics during the core-hole lifetime.In contrast to the single core ionized Water Molecule, we found that dissociation dynamics of double core-ionized Water have strong effect on the resulting electron emission spectra. In addition, we found that the single core hole lifetime is slightly smaller than the value obtained in earlier theoretical works. Finally, we predict that the lifetime of double core ionized states is significantly lower than half of the lifetime of a single core hole.

Liangbing Gan - One of the best experts on this subject based on the ideXlab platform.

  • open cage fullerene with a stopper acts as a molecular vial for a single Water Molecule
    Organic chemistry frontiers, 2015
    Co-Authors: Sisi Liang, Liangbing Gan, Jiahao Sun
    Abstract:

    An open-cage fullerene derivative with three carbonyl groups on the rim of the orifice reacts with o-diaminobenzene reversibly to form a tetrahydrofuran moiety above the orifice. Water encapsulation and release experiments show that the tetrahydrofuran moiety acts as a stopper effectively blocking the orifice. The addition and removal of o-diaminobenzene serve as a chemically controlled switching process for the fullerene-based Water container, which is suited for just one Water Molecule due to its moderate cavity size.

  • open cage fullerenes as tailor made container for a single Water Molecule
    Journal of Physical Organic Chemistry, 2013
    Co-Authors: Lijun Shi, Liangbing Gan
    Abstract:

    Water is the most important liquid on earth. Clusters of Water have been investigated extensively in an effort to understand the bulk property of Water. But the behavior of single Water Molecule without H-bond has been rarely studied. Open-cage [60]fullerenes have been shown to trap a single Water Molecule selectively over Molecules with comparable size and act as the smallest “Water bottle”. Copyright © 2013 John Wiley & Sons, Ltd.

C A Ward - One of the best experts on this subject based on the ideXlab platform.

  • area occupied by a Water Molecule adsorbed on silica at 298 k zeta adsorption isotherm approach
    Journal of Physical Chemistry C, 2020
    Co-Authors: Nagarajan Narayanaswamy, C A Ward
    Abstract:

    The zeta adsorption isotherm, ZAI, is used with heterogeneity-free adsorption measurements, reported by Baker and Sing, to determine the area of a Water Molecule adsorbed on TK800 silica at 298 K. ...

  • area occupied by a Water Molecule adsorbed on silica at 298 k zeta adsorption isotherm approach
    The Journal of Physical Chemistry, 2020
    Co-Authors: Nagarajan Narayanaswamy, C A Ward
    Abstract:

    The zeta adsorption isotherm, ZAI, is used with heterogeneity-free adsorption measurements, reported by Baker and Sing, to determine the area of a Water Molecule adsorbed on TK 800 silica at 298 K. We examine this value by using measured Water vapor adsorption isotherms of three non-TK 800 silicas, convert them to thermodynamic adsorption isotherms, and show that they coincide. Then, all four Water adsorption measurements are pooled to form a single data set and used to formulate a thermodynamic isotherm for Water vapor on silica. We then examine the stability of the adsorbate as a function of the vapor-phase pressure, Pⱽ. This analysis indicates that a phase change occurs for silica when Pⱽ reaches the value of a ZAI constant and this is interpreted as the wetting transition, which is assumed to transform the solid–vapor surface energy to that of the liquid–vapor interface. These assumptions are examined using the ZAI thermodynamic isotherm and the Gibbs adsorption equation to predict the surface energy of any fully hydroxylated silica in the absence of adsorption. Further examination showed that the number of adsorption sites determined by the ZAI corresponds to the surface concentration of silanol groups, which act as centers of Water vapor adsorption.

Yajiang Hao - One of the best experts on this subject based on the ideXlab platform.

  • x ray multiphoton ionization dynamics of a Water Molecule irradiated by an x ray free electron laser pulse
    Physical Review A, 2016
    Co-Authors: Ludger Inhester, Kota Hanasaki, Sangkil Son, Robin Santra, Yajiang Hao
    Abstract:

    We present a theoretical investigation of x-ray multiphoton ionization dynamics of polyatomic Molecules, based on the rate equation model and molecular electronic structure calculations. An efficient numerical procedure is developed to calculate photoionization cross sections, Auger rates, and fluorescence rates for all possible electronic multiple-hole configurations of Molecules. We investigate the charge-state distribution of a Water Molecule after interaction with an intense x-ray pulse and discuss its dependence on the fluence and the pulse duration of the x-ray beam. Our results demonstrate that a Water Molecule exposed to an intense x-ray pulse is more ionized than what would be expected within the independent-atom picture.