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Referring to a recent experiment, we theoretically study the process of a two-channel decay of the diatomic silver anion (Ag$_2^-$), namely the spontaneous electron ejection giving Ag$_2$ + e$^-$ and the dissociation leading to Ag$^-$ + Ag. The ground state potential energy curves of the silver molecules of diatomic neutral and negative ion were calculated using proper pseudo-potentials and atomic basis sets. We also estimated the non-adiabatic electronic coupling between the ground state of Ag$_2^-$ and the ground state of Ag$_2$ + e$^-$, which in turn allowed us to estimate the minimal and mean values of the electron autodetachment lifetimes. The relative energies of the rovibrational levels allow the description of the spontaneous electron emission process, while the description of the rotational dissociation is treated with the quantum dynamics method as well as time-independent methods. The results of our calculations are verified by comparison with experimental data., Comment: The data that support the findings of this study are openly available in MOST Wiedzy at https://mostwiedzy.pl/en/open-research-data-series/niema,202103311024423091181-0/catalog

We present an extensive range of quantum calculations for the state-changing rotational dynamics involving two simple molecular anions which are expected to play some role in evolutionary analysis of chemical networks in the Interstellar environments, C$_2$H$^-$($X^1\Sigma^+$) and C$_2$N$^-$ ($X^3 \Sigma^-$) but for which inelastic rates are only known for C$_2$H$^-$. The same systems are also of direct interest in modelling selective photo-detachment (PD) experiments in cold ion traps where the He atoms function as the chief buffer gas at the low trap temperatures. This study employs accurate, \textit{ab initio} calculations of the interaction potential energy surfaces (PESs) for these anions, treated as Rigid Rotors (RR) and the He atom to obtain a wide range of state-changing quantum cross sections and rates at temperatures up to about 100 K. The results are analysed and compared for the two systems, to show differences and similarities between their rates of state-changing dynamics.

This paper proposes a novel method to identify unexpected structures in 2D floor plans using the concept of Bayesian Surprise. Taking into account that a person's expectation is an important aspect of the perception of space, we exploit the theory of Bayesian Surprise to robustly model expectation and thus surprise in the context of building structures. We use Isovist Analysis, which is a popular space syntax technique, to turn qualitative object attributes into quantitative environmental information. Since isovists are location-specific patterns of visibility, a sequence of isovists describes the spatial perception during a movement along multiple points in space. We then use Bayesian Surprise in a feature space consisting of these isovist readings. To demonstrate the suitability of our approach, we take "snapshots" of an agent's local environment to provide a short list of images that characterize a traversed trajectory through a 2D indoor environment. Those fingerprints represent surprising regions of a tour, characterize the traversed map and enable indoor LBS to focus more on important regions. Given this idea, we propose to use "surprise" as a new dimension of context in indoor location-based services (LBS). Agents of LBS, such as mobile robots or non-player characters in computer games, may use the context surprise to focus more on important regions of a map for a better use or understanding of the floor plan., Comment: 10 pages, 16 figures