Insights into the geometries, electronic and magnetic properties of neutral and charged palladium clusters

We performed an unbiased structure search for low-lying energetic minima of neutral and charged palladium Pd(n)(Q) (n = 2–20, Q = 0, + 1 and –1) clusters using CALYPSO method in combination with density functional theory (DFT) calculations. The main candidates for the lowest energy neutral, cationic and anionic clusters are identified, and several new candidate structures for the cationic and anionic ground states are obtained. It is found that the ground state structures of small palladium clusters are more sensitive to the charge states. For the medium size Pd(n)(0/+/–) (n = 16–20) clusters, a fcc-like growth behavior is found. The structural transition from bilayer-like structures to cage-like structures is likely to occur at n = 14 for the neutral and cationic clusters. In contrast, for the anionic counterparts, the structural transition occurs at Pd(13)(–). The photoelectron spectra (PES) of palladium clusters are simulated based on the time-dependent density functional theory (TD-DFT) method and compared with the experimental data. The good agreement between the experimental PES and simulated spectra provides us unequivocal structural information to fully solve the global minimum structures, allowing for new molecular insights into the chemical interactions in the Pd cages

Computational Thinking Nurturing Skills and Inspiring Pedagogy for Sustainable Education in the 21st Century

International audienceCreativity, Innovation, Information search, problem-solving and data treatment are important not only in developed countries where people use many digital objects in their everyday life. Developing countries are necessary concerned by many aspects of the information society and digital era. Even if a large part of the population still does not access to the internet, because of a lack of reliable infrastructure, the information and knowledge societies are imposing their pace of innovation to the entire world. A more and more complex world is coming. Developing countries also feel the need to educate their people and give them the most of the 21st century skillset in order to face this complexity and the new challenges. For this reason, and because some of these competencies can be taught even without computers, Computational Thinking may nurture these skills even in developing countries.In this presentation, we try to show how the integration of Computational Thinking with collaborative problem-based learning can cultivate learners how to learn and work on a real (authentic) problem together by bridging computer science main concepts and these skills to some efficient collaborative learning methods. Different recent viewpoints from developing countries are presented to show how they face this challenge in their nation

Structural, Electronic, and Magnetic Properties of Bimetallic Ni m Nb n (m + n ≤ 8) Clusters: First Principle Study

Structural, electronic, and magnetic properties of bimetallic NimNbn(m + n≤8) clusters have been investigated using the particle swarm optimization coupled with density functional theory. Ninety-seven stable structures of Ni mNb n clusters were found. Among these Ni mNb n clusters, most of the ground state of bimetallic clusters prefers compact structures when m + n>3. The HOMO–LUMO gaps of these bimetallic Ni mNb n clusters were found in the range of 0.1–0.5 eV. The exchange splitting exists in most of these binary clusters and results in non-zero magnetization in these clusters. Most of the clusters show their magnetic moment strongly depending on the size, the symmetry, the configuration, and the composition. An interesting finding is that the magnetic moment per atom in NiNb and Ni2Nb clusters shows a larger value (i.e., 1.5 and 1.0 μB) than that of the corresponding size of pure Ni clusters.</p

Code ABC MOOC for math teachers

Computing is the latest add-on to enhance the K-12 curricula of many countries, with the purpose of closing the digital skills gap. The revised Finnish Curriculum 2014 integrates computing mainly into math. Consequently, Finland needs to train math teachers to teach computing at elementary level. This study describes the Python and Racket tracks of the Code ABC MOOC that introduce programming basics for math teachers. Their suitability for math is compared based on the course content and feedback. The results show that conceptually the functional paradigm of Racket approaches math more closely, in particular algebra. In addition, Racket is generally regarded as more challenging in terms of syntax and e.g. for utilizing recursion as an iteration mechanism. Math teachers also rank its suitability higher because the content and exercises of the track are specifically tailored for their subject.acceptedVersionPeer reviewe