Microsolvation of a Proton by Ar Atoms: Structures and Energetics of ArH Clusters.

We present a computational investigation on the structural arrangements and energetic stabilities of small-size protonated argon clusters, Ar nH +. Using high-level ab initio electronic structure computations, we determined that the linear symmetric triatomic ArH +Ar ion serves as the molecular core for all larger clusters studied. Through harmonic normal-mode analysis for clusters containing up to seven argon atoms, we observed that the proton-shared vibration shifts to lower frequencies, consistent with measurements in gas-phase IRPD and solid Ar-matrix isolation experiments.

Computational Modeling: Up-to-Date Approaches and Cutting-Edge Applications from Clusters, Nanostructures to Bulk Systems.

The contributions in this special theme collection, in honor to Prof. P. Villarreal, cover a broad variety of computational methodologies and experimental techniques, containing studies on gas phase, clusters and condensed phase systems.

CO2 inside sI clathrate-like cages: Automated construction of neural network/machine learned guest-host potential and quantum spectra computations.

We present new results on the underlying guest-host interactions and spectral characterization of a CO2 molecule confined in the cages of the sI clathrate hydrate. Such types of porous solids raise computational challenges, as they are of practical interest as gas storage/capture materials. Accordingly, we have directed our efforts toward addressing their modeling in a proper manner, ensuring the quality of the input data and the efficiency of the computational approaches.

A kernel-based machine learning potential and quantum vibrational state analysis of the cationic Ar hydride (ArH).

One of the most fascinating discoveries in recent years, in the cold and low pressure regions of the universe, was the detection of ArH and HeH species. The identification of such noble gas-containing molecules in space is the key to understanding noble gas chemistry. In the present work, we discuss the possibility of [ArH] existence as a potentially detectable molecule in the interstellar medium, providing new data on possible astronomical pathways and energetics of this compound.

Analysing the stability of He-filled hydrates: how many He atoms fit in the sII crystal?

Clathrate hydrates have the ability to encapsulate atoms and molecules within their cavities, and thus they could be potentially large storage capacity materials. The present work studies the multiple cage occupancy effects in the recently discovered He@sII crystal. On the basis of previous theoretical and experimental findings, the stability of He@sII, He@sII and He@sII crystals was analysed in terms of structural, mechanical and energetic properties.