Finite size dependent dispersion potentials between atoms and ions dissolved in water

Non-Reciprocal Interactions Induced by Water in Confinement

Water mediates electrostatic interactions via the orientation of its dipoles around ions, molecules, and interfaces. This induced water polarization consequently influences multiple phenomena. In particular, water polarization modulated by nanoconfinement affects ion adsorption and transport, biomolecular self-assembly, and surface chemical reactions. Therefore, it is of paramount importance to understand how water-mediated interactions change at the nanoscale. Here we show that near the graphene surface anion-cation interactions do not obey the translational and isotropic symmetries of Coulom…

Anion emission from water molecules colliding with positive ions: Identification of binary and many-body processes

It is shown that negative ions are ejected from gas-phase water molecules when bombarded with positive ions at keV energies typical of solar-wind velocities. This finding is relevant for studies of planetary and cometary atmospheres, as well as for radiolysis and radiobiology. Emission of both H- and heavier (O- and OH-) anions, with a larger yield for H-, was observed in 6.6-keV 16O+ + H2O collisions. The ex-perimental setup allowed separate identification of anions formed in collisions with many-body dynamics from those created in hard, binary collisions. Most of the ani-ons are emitted with…

Spectra of secondary electrons generated in water by energetic ions

The energy distributions of secondary electrons produced by energetic carbon ions (in the energy range used, e.g., in hadron therapy), incident on liquid water, are discussed. For low-energy ions, a new parameterization of the singly-differential ionization cross sections is introduced, based on tuning the position of the Bragg peak. The resulting parameterization allows a fast calculation of the energy spectra of secondary electrons at different depths along the ion's trajectory, especially near the Bragg peak. At the same time, this parameterization provides penetration depths for a broad ra…

水及其分子离子直至H$_2$O$^{3+}$的势能面

Potential-energy surfaces of water and its molecular ions up to H$_2$O$^{3+}$

本研究计算了水及其分子离子（至H$_2$O$^{3+}$）的势能面，通过基准测试确定了基于CASSCF的准确方法，为未来水与自由电子激光相互作用研究及推广至其他三原子分子奠定基础。

Anion and cation emission from water molecules after collisions with 6.6-keV $^{16}$O$^{+}$ ions

Anion and cation emission following water dissociation was studied for 6.6-keV $^{16}$O$^{+}$ + H$_{2}$O collisions. Absolute cross sections for the emission of all positively and negatively charged fragments, differential in both energy and observation angle, were measured. The fragments formed in hard, binary collisions appearing in peaks were distinguishable from those created in soft collisions with many-body dynamics that result in a broad energy spectrum. A striking feature is that anions and cations are emitted with similar energy and angular distributions, with a nearly constant ratio …

Two-center dielectronic recombination

In the presence of a neighboring atom, electron-ion recombination can proceed resonantly via excitation of an electron in the atom, with subsequent relaxation through radiative decay. It is shown that this two-center dielectronic process can largely dominate over single-center radiative recombination at internuclear distances as large as several nanometers. The relevance of the predicted process is demonstrated by using examples of water-dissolved alkali cations and warm dense matter.