Workshop on Crystal Structure Prediction: Exploring the Mendeleev Table as a Palette to Design New Materials
ICTP, Trieste, 14-18 January 2019
Thanks to enormous progress in computing power and in algorithm development, we are now closer to being able to predict the crystal structure of any material from the simple knowledge of its composition. This is the first necessary step for predicting in silico the property of a material, and planning modifications that could improve these properties. A critical discussion of the algorithms developed in the last years for the “in silico” prediction of crystal structures was the main theme of a workshop that took place at the Abdus Salam International Centre for Theoretical Physics (ICTP), in Trieste, Italy, from 14 to 18 January 2019. The event, titled “Workshop on Crystal Structure Prediction: Exploring the Mendeleev Table as a Palette to Design New Materials”, focused in particular on approaches based on molecular modeling and was an opportunity to celebrate 2019 as the International Year of the Periodic Table, since crystal structure prediction is rooted in a deep knowledge of the properties of the atoms, and, in turn, numerous discoveries made with the help of crystal structure prediction, reveal new (often completely unexpected) sides of the behavior of the atoms. The Workshop was directed by the A. Laio, G. Desiraju, A. Oganov, and S. Scandolo. It was divided in two parts: the first three days were dedicated to an in-depth and critical discussion of the methods, with talks given by world experts in the field. The last two days were devoted to “hands-on” computer labs were the younger participants were given the opportunity to learn how to use the most advanced codes for crystal structure prediction, including the “Universal Structure Predictor: Evolutionary Xtallography” (USPEX) and the “Ab initio Random Structure Searching” (AIRSS). Continue reading Report on Workshop on Crystal Structure Prediction: Exploring the Mendeleev Table as a Palette to Design New Materials→
Today, many open questions in computational science call for more than individual computations using a single code. As the demand for integration and throughput increases, the skill of writing robust and reproducible workflows is becoming ever more important. In this context, the move towards open science raises the level of scrutiny and demands that workflows be recorded in a way that can be inspected and reused by scientific peers.
This hands-on tutorial introduced young researchers to writing reproducible computational workflows using the open-source AiiDA framework for workflow management and provenance tracking (http://www.aiida.net), complemented by invited talks from experts in the field that highlight the power and the challenges involved with leveraging complex workflows in computational materials science.
The Atomistic Simulation of Carbon and related Materials (ASCM2019) workshop (ascm2019.nanocarbon.fi) took place in Helsinki, Finland between the 10th and 12th of April 2019. The workshop venue was the historical main building of the University of Helsinki. The event was jointly organized by Flyura Djurabekova (University of Helsinki), Volker Deringer (University of Cambridge) and Miguel Caro (Aalto University).
A total of circa 45 participants (mostly from Europe but also from overseas) met at the heart of Helsinki for three days of discussion on the state of the art and future prospects of atomistic simulation of pure carbon compounds and nanostructures, functionalized carbon materials, carbon-containing molecules and silicon/SiC alloys. Focus topics with strong presence at the workshop were atomistic modeling of graphene and carbon nanotubes, amorphous carbon, molecular dynamics simulations of high-energy/irradiation effects, development and benchmarking of interatomic potentials and, prominently, machine learning applied to atomistic simulations in general and carbon science in particular. The oral sessions featured a nice combination of established and early-career researchers.
The main objective of the workshop “Green’s function methods: the next generation”, arrived at its 4-th edition, is to bring together an interdisciplinary audience of researchers dealing with Green’s functions methods and electron correlation. Both fundamental developments and high-end applications are targeted, together with discussions on numerical implementations and their current limitations.
Green’s functions have always played a prominent role in many-body physics. In particular the one-body Green’s function (GF) delivers a wealth of information about a physical system, such as ground-state energy, excitation energies, densities and other measurable quantities. Therefore the development of approximate methods to calculate the one-body GF has been an active research topic in many-body physics since the 60’s, and many routes have been explored in order to find increasingly accurate GFs. A very popular class of methods is based on the iterative solution of an integral equation for the GF containing an effective potential, the so-called self-energy, which needs to be approximated. The well-known GW approximation belongs to this class; this approximation is the method of choice for calculating band structures, but it also shows several shortcomings, such as the wrong description of satellites in photo-emission spectra, in particular in so-called strongly-correlated materials. Therefore more refined levels of approximations are needed to keep the pace with the advances made in experiment. Recently much progress has been made in this direction both by going beyond standard methods and also exploring completely novel routes to calculate GF. A new wave of original ideas, understanding, and solutions, has pervaded the field and was represented in the present workshop.
Workshop Report What about U in nanoscale systems?
ZCAM/BIFI, Zaragoza, Spain, May 21-24 2019
Organizers: David Jacob (UPV/EHU, San Sebastian), Massimo Capone (SISSA, Trieste), Silke Biermann (Ecole Polytechnique, Paris)
Local Organizers: Beatriz Antoli, Adrian Velazquez-Campoy (ZCAM, BIFI, Zaragoza)
The Workshop “What about U in nanoscale systems?” took place at the CECAM node in Zaragoza from May 21 to May 24 2019. It followed the format of previous What about U editions, bringing together colleagues from different communities (including experimentalists) and providing ample discussion time. The new aspect this year was the focus on nanoscale systems, while also general aspects of correlations found their place. Continue reading What about U in nanoscale systems?→
The workshop aimed at bringing together experimentalists and theorists dealing with electronic structure investigations in correlated materials. Strongly correlated materials are notoriously difficult to describe theoretically due to the competing energy scales and emerging phenomena (like the Kondo effect) coming into play while at the same time experiments can provide a wealth of results whose interpretation often proves overwhelmingly challenging. It is therefore pivotal to bring together physicists investigating such materials theoretically or experimentally, to provide a common platform for discussions and encourage mutual insight into problems and results. This workshop aimed at exactly such an information exchange. Experimentally, recent advances in angle- and spin-resolved photoemission spectroscopy and scanning tunneling spectroscopy are leading examples for providing information about the materials’ electronic structure while cutting-edge density functional theory and dynamical mean field theory have developed into powerful tools for electronic structure calculations. Strongly correlated materials of interest ranged from transition metal compounds to f-electron systems. Of particular interest were also topological materials. Continue reading Workshop on Advances in Electron Spectroscopy – Experiment and Theory, April 14-17, 2019, Dresden→
The workshop took place in April 2019 in Göttingen and brought together leading researchers who develop and apply machine learning methods with the common goal of determining the fundamental properties of “small” molecules, biomolecules, and materials. These properties include high-dimensional potential energy surfaces, atomic densities, and molecular properties, such as dipole moments and polarizabilities. Communities in the areas of materials, biomolecules, gas-phase molecules and complexes have formed over the past ten or so years and a major objective of the workshop was to bring these communities together to hear and learn from each other’s experience.
In 2018, the ETSF Young Researchers’ Meeting took place in Hamburg, Germany. The hottest summer in the history of Hamburg, the well prepared Center for Free Electron Laser Science (CFEL) and more than sixty motivated researcher built the perfect frame
for a stimulating week full of science.
The Young Researchers’ Meeting (YRM) of the European Theoretical Spectroscopy Facility (ETSF) is an annual conference organized and attended exclusively by researchers without permanent position that work on state-of-the-art theoretical and computational methods for the study of electronic and optical properties of materials.
YRM is the place to present your work in progress, come up with new ideas and learn about others’ work in a friendly and open atmosphere. Master students, PhD students as well as young post-docs from all over Europe came together and discussed latest
advances in their fields. This year, talks at the YRM were 20 minutes, including 5 minutes of discussion. This gave everyone enough time to communicate his or her findings and receive feedback from other participants.
The Thomas Young Centre (TYC) held their 5th Energy workshop, entitled “From Atoms to Applications” from the 25th to the 27th of July 2018 at the Department of Chemistry in University College London. The meeting was focussed on the evolution of computational materials design, specifically for Energy Materials. The aim of the workshop was to showcase the latest advances in computational materials design and to promote discussion and debate on bridging theory and experiment. We had a range of excellent speakers on the side of theory and of experiment, and it was clear from the discussions after talks and at the coffee breaks and lunches that the combination of theory and experiment is alive and thriving. The programme featured invited talks from established leaders in the field and from emerging early career researchers in the area. We scheduled 15 minutes for questions after every presentation, and this prompted lively discussion and debate. We had 99 attendees ranging from established academics, to PDRAs, PhD students and even Undergraduate students, with representation by Senior Editors from Nature and Nature Materials. The workshop featured diverse energy applications such as oxide and proton conducting fuel cells, photocatalysis, photovoltaics, LEDs, catalysis, solid state batteries, organic electronics and amorphous oxides semiconductors.
Organizers: Tim O. Wehling (Bremen), Thomas Frauenheim (Bremen), Silke Biermann (Palaiseau Cedex), Johannes Lischner (London), Nikolay Prokofiev (Amherst, Massachusetts), Malte Schüler (Bremen), Andrew Millis (New York)
Venue: University of Bremen, Bremen Center for Computational Materials Science (BCCMS), Germany, 8th until 12th of October 2018
Sponsors: University of Bremen (BCCMS), Psi-k, DFG, CECAM
Electrons in real materials are subject to Coulomb interaction among each other. This interaction is long-ranged, gives rise to correlation effects, and often poses fundamental problems in ab initio simulations of real materials. A nowadays commonly used ab initio approach for strongly correlated materials is the augmentation of density functional (DFT) based methods with many-body treatments of the Hubbard model, such as the combination of DFT and dynamical mean field theory . This approach, however, neglects all correlation effects stemming from non-local Coulomb interaction, since the Hubbard model only includes the on-site part of the interaction. Combining more sophisticated diagrammatic ab initio methods (GW) with methods and models which contain the long-range contributions of the interaction (EDMFT)  alleviates these problems in part but comes with the introduction of further approximations. Assessing the quality of such approaches is currently hampered by the fact that even the extended Hubbard model, which is the minimal many-body model capturing explicitly non-local interactions, is at best partially understood.Continue reading Report: CECAM / PSI-K Workshop Bremen on Correlated electron physics beyond the Hubbard model→
Ab initio (from electronic structure) calculation of complex processes in materials