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The abstract is available here: https://uscholar.univie.ac.at/o:1633179

We report the non-adiabatic dynamics of VIIICl3(ddpd), a complex based on the Earth-abundant first-row transition metal vanadium with a d2 electronic configuration which is able to emit phosphorescence in solution in the near-infrared spectral region. Trajectory surface-hopping dynamics based on linear vibronic coupling potentials obtained with CASSCF provide molecular-level insights into the intersystem crossing from triplet to singlet metal-centered states. While the majority of the singlet population undergoes back-intersystem crossing to the triplet manifold, 1–2% remains stable during the 10 ps simulation time, enabling the phosphorescence described in Dorn et al. Chem. Sci., 2021, DOI: 10.1039/D1SC02137K. Competing with intersystem crossing, two different relaxation channels via internal conversion through the triplet manifold occur. The nuclear motion that drives the dynamics through the different electronic states corresponds mainly to the increase of all metal–ligand bond distances as well as the decrease of the angles of trans-coordinated ligand atoms. Both motions lead to a decrease in the ligand-field splitting, which stabilizes the interconfigurational excited states populated during the dynamics. Analysis of the electronic character of the states reveals that increasing and stabilizing the singlet population, which in turn can result in enhanced phosphorescence, could be accomplished by further increasing the ligand-field strength., The ultrafast triplet-to-singlet mechanism, responsible for the photoluminescence of the open-shell VIIICl3(ddpd) complex – based on Earth-abundant vanadium – is unraveled using non-adiabatic dynamics in full dimensionality.

Animal monitoring in natural habitats provides significant insights into the animals��� behavior, interactions, health, or external influences. However, the sizes of monitoring devices attachable to animals strongly depends on the animals��� sizes, and thus the range of possible sensors including batteries is severely limited. Gathered data can be offloaded from monitoring devices to data sinks in a wireless sensor network using available radio access technologies, but this process also needs to be as energy-efficient as possible. This paper presents an approach to combine the benefits of high-throughput WiFi and robust low-power LoRa communication for energy-efficient data offloading. WiFi is only used when connectivity between mobile devices and data sinks is available, which is determined by LoRa-based distance estimations without the need for additional GPS sensors. A prototypical implementation on low-end commodity-off-the-shelf hardware is used to evaluate the proposed approach in a German mixed forest using a simple path loss model for distance estimation. The system provides an offloading success rate of 87%, which is similar to that of a GPS-based approach, but with around 37% less power consumption.

Multichannel dispersed emission spectra originated upon a selective excitation of Rydberg electronic energy states in the ZnAr and CdAr van der Waals (vdW) complexes are simulated and analysed as a proof-of-concept of the future experimental approach. Simulations of the emission spectra are based on ab-initio calculated interatomic potentials and transition dipole moments (TDMs), that for ZnAr were newly calculated. Experimental set-up that is under construction along with the experimental procedure are discussed.

We describe the state-of-the-art in performance modeling and prediction for Information Retrieval (IR), Natural Language Processing (NLP) and Recommender Systems (RecSys) along with its shortcomings and strengths. We present a framework for further research, identifying five major problem areas: understanding measures, performance analysis, making underlying assumptions explicit, identifying application features determining performance, and the development of predic- tion models describing the relationship between assumptions, features and resulting performance

We show that the use of the IPEA correction in CASPT2 for excited state calculations of organic chromophores is not justified., Multi-configurational second order perturbation theory (CASPT2) has become a very popular method for describing excited-state properties since its development in 1990. To account for systematic errors found in the calculation of dissociation energies, an empirical correction applied to the zeroth-order Hamiltonian, called the IPEA shift, was introduced in 2004. The errors were attributed to an unbalanced description of open-shell versus closed-shell electronic states and is believed to also lead to an underestimation of excitation energies. Here we show that the use of the IPEA shift is not justified and the IPEA should not be used to calculate excited states, at least for organic chromophores. This conclusion is the result of three extensive analyses. Firstly, we survey the literature for excitation energies of organic molecules that have been calculated with the unmodified CASPT2 method. We find that the excitation energies of 356 reference values are negligibly underestimated by 0.02 eV. This value is an order of magnitude smaller than the expected error based on the calculation of dissociation energies. Secondly, we perform benchmark full configuration interaction calculations on 137 states of 13 di- and triatomic molecules and compare the results with CASPT2. Also in this case, the excited states are underestimated by only 0.05 eV. Finally, we perform CASPT2 calculations with different IPEA shift values on 309 excited states of 28 organic small and medium-sized organic chromophores. We demonstrate that the size of the IPEA correction scales with the amount of dynamical correlation energy (and thus with the size of the system), and gets immoderate already for the molecules considered here, leading to an overestimation of the excitation energies. It is also found that the IPEA correction strongly depends on the size of the basis set. The dependency on both the size of the system and of the basis set, contradicts the idea of a universal IPEA shift which is able to compensate for systematic CASPT2 errors in the calculation of excited states.

Jenny Zobel, fille de l’écrivain martiniquais Joseph Zobel, et Emily Zobel Marshall, petite-fille de Joseph Zobel, ont découvert récemment des manuscrits inédits de leur père et grand-père. Il s’agit, d’une part, d’une collection de lettres envoyées par Joseph en 1946-1947 depuis Paris à sa femme et à son ami martiniquais Valbrun Apat, et, d’autre part, d’extraits de son journal intime des années 1940. Elles nous proposent une analyse qui répondrait à la question « Qu’apporte la lecture de ces manuscrits à l’étude des œuvres de Joseph Zobel ? »1

Welcome to SIGIR 2016, the 39th Annual International ACM-SIGIR Conference on Research and Development in Information Retrieval, the premier conference in the area. We are grateful to all those who chose to submit their research papers to SIGIR 2016 and gave the Program Committee an opportunity to evaluate their work for potential inclusion in the program. We are also grateful to the 61 Senior Program Committee Members, 244 Program Committee Members, and many additional reviewers for providing significant time and effort to selecting this year's conference program. This pool of committed SIGIR volunteers comes from 24 countries and over 180 institutions. The PC reviewed 341 papers for the full paper track, and accepted 62 with an acceptance rate of 18%. The top countries in terms of accepted papers (taking all author affiliations of each paper equally into account) were the U.S.A. (34%), and China (23%) with the most successful countries (as measured by how likely authors from that country were to have their papers accepted) were Russia (55% of authors had their paper accepted), Israel (50%), and Germany (45%). With 1236 authors overall, 313 were from the U.S.A and 283 from China; and 289 from the next six most represented countries combined. As has been customary for many years, SIGIR 2016 employed a two-tier double-blind review process. At least three reviewers reviewed each paper, and then the Primary Area Chair of the paper led a discussion, which was used as the basis of the meta-review. The Secondary Area Chair assigned to each paper double-checked the reviews and discussion and, in some cases, provided an additional review. The PC chairs carefully examined the reviews and associated discussion, asking for additional reviews where necessary to provide a fuller discussion or additional expert opinion. The SIGIR 2016 PC meeting operated as a virtual meeting, held over several days, in order tofacilitate the involvement of as many Senior PC members as possible. Prior to the PC meeting the PC chairs proposed a list of "clear accepts" and "clear rejects" where the meta-reviews and reviews clearly indicated a decision. Over the four days of the PC meeting, the chairs indicated which undecided papers were open for discussion, led the discussion on these papers, and made the final decision when discussions moved towards completion; overall nearly half of the submitted papers were reviewed by the chairs or at the meeting. We are grateful for the involvement of the Senior PC members in supporting this PC meeting, especially those very committed members who participated in almost every discussion. The virtual PC meeting was supplemented by a small physical meeting of the Senior PC members who attended the ECIR 2016 conference, which took place during the same week. The short paper track received 339 submissions and accepted 104 papers for what promises to be a strong short paper track. Thanks are due to Ben Carterette, Carlos Castillo, and Jaana Kekäläinen, the track chairs, for arranging and managing a thorough review process for so many papers -- a huge effort for which we are very grateful. The tutorial track reviewed 20 submissions and accepted 2 full-day tutorials and 10 half-day tutorials. We are grateful to Evangelos Kanoulas and Tie-Yan Liu for leading the selection of a diverse and high quality tutorial program. The workshops track received 12 submissions and selected 7 workshop proposals. We thank Aristides Gionis and Edie Rasmussen for their efforts in producing a great set of workshops. The demos track received 35 submissions of which 21 were accepted. Many thanks are due to Craig Macdonald for chairing this track and providing us with an array of interesting demos. Brian D. Davison and Kira Radinsky organised the Doctoral Consortium, a vitally important part of the SIGIR program. Thanks to their efforts, the event received 23 submissions from doctoral students and accepted 15 of these for presentation and discussion at the consortium. This year's industry track is the SIGIR Symposium on IR in Practice (SIRIP 2016) co-chaired by Jussi Karlgren and Gilad Mishne. Their efforts in organizing SIRIP and producing an interesting set of speakers from diverse backgrounds are gratefully acknowledged.

Ranked retrieval has a particular disadvantage in comparison with traditional Boolean retrieval: there is no clear cut-off point where to stop consulting results. This is a serious problem in some setups. We investigate and further develop methods to select the rank cut-off value which optimizes a given effectiveness measure. Assuming no other input than a system's output for a query--document scores and their distribution--the task is essentially a score-distributional threshold optimization problem. The recent trend in modeling score distributions is to use a normal-exponential mixture: normal for relevant, and exponential for non-relevant document scores. We discuss the two main theoretical problems with the current model, support incompatibility and non-convexity, and develop new models that address them. The main contributions of the paper are two truncated normal-exponential models, varying in the way the out-truncated score ranges are handled. We conduct a range of experiments using the TREC 2007 and 2008 Legal Track data, and show that the truncated models lead to significantly better results.

In this paper we explore the use of category information for ad hoc retrieval in Wikipedia. We show that techniques for entity ranking exploiting this category information can also be applied to ad hoc topics and lead to significant improvements. Automatically assigned target categories are good surrogates for manually assigned categories, which perform only slightly better.

This paper describes a simple clustering approach to person name disambiguation of retrieved documents. The methods are based on standard IR concepts and do not require any task-specific features. We compare different term-weighting and indexing methods and evaluate their performance against the Web People Search task (WePS). Despite their simplicity these approaches achieve very competitive performance.

Transcripts of meetings are a document genre characterized by a complex narrative structure. The essence is not only what is said, but also by who and to whom. This paper investigates whether we can use semantic annotations like the speaker in order to capture this debate structure, as well as the related content of the debate. The structure is visualized in a graph, while the content is condensed into word clouds, that are created using a parsimonious language model. Evaluation shows that both tools adequately capture the structure and content of the debate at an aggregated level.

In my research, I propose a coherence measure, with the goal of discovering and using topic structures within and between documents, of which I explore its extensions and applications in information retrieval.

We present a semantic approach to suggesting query completions which leverages entity and type information. When compared to a frequency-based approach, we show that such information mostly helps rare queries.