Structural diversity in sodium doped water trimers

Abstract

The structures of sodium doped water trimers are characterized on the basis of their infrared action spectra in the OH-stretching region and a global optimization approach to identify the lowest energy minima. The most stable structure is an open ring with two contacts of terminal water molecules to the Na atom. This structure explains the dominating feature in the IR depletion spectrum around 3410 cm(-1). Three additional isomer classes were found in an energy window of 12 kJ mol(-1) with vertical ionization energies ranging from ∼3.83 eV to ∼4.36 eV. These structures show different hydrogen bonding and sodium coordination patterns and are identified by specific spectral features in the IR spectra. The significant abundance of closed rings with an external Na atom, resembling the undoped water trimer, suggests that for larger clusters the picture of the sodium atom being situated on the cluster surface seems adequate.

Catalytic activity of water molecules in gas‐phase glycine dimerization

“…In practice, a cutoff is imposed on the number of iterations and the energy change between iterations. For the current study, we used the GA implemented in OGOLEM [ 55–62 ] with the PM7 [ 63 ] semiempirical PES implemented in MOPAC 2016. [ 63–67 ] Each TS(H 2 O) n cluster consisted of a frozen transition state extracted from Dornshuld et al surrounded by n water molecules.…”

Exploring self‐organization of molecular tether molecules on a gold surface by global structure optimization

“…Hence, tackling the assembly of a dozen TATA molecules on rigid Au(111) with nondiscretized global optimization directly using ab initio, DFT or semiempirical methods simply is not feasible. Even for clusters of small molecules like water, unrestricted global optimization at the DFT level is computationally feasible only for very small cluster sizes up to three to five molecules …”

The temperature and size distribution of large water clusters from a non-equilibrium model

“…7,11 In contrast, only relative temperatures (like expansion A is colder/warmer than expansion B) are usually reported for size-selectively performed molecular beam based studies. [12][13][14] In some special cases, an elegant spectrometric approach to cluster temperatures is possible, based on the measurements of rotational temperatures. [15][16][17] Another approach makes use of Laval nozzles with a fixed geometry.…”