Total Energy and Force Methods 2018 Selwyn College, Cambridge, UK 9th – 11th January 2018
Organisers: Chris Pickard (University of Cambridge), Gábor Csányi (University of Cambridge), Mike Payne (University of Cambridge), Richard Needs (University of Cambridge), Michiel Sprik (University of Cambridge); External advisor: Mike Finnis (Imperial College London).
Funding: Psi-k, CCP9, the UKCP Consortium and the EPSRC CDT in Computational Methods for Materials Science.
This event was the latest in the “mini” series associated with the “Total Energy and Forces” workshops, held at ICTP in Trieste every two years. Since 1987 the Trieste workshops have taken place in odd-numbered years, alternating with the mini workshops, held each even-numbered year in a different location. The most recent workshops of the mini series took place in Madrid (2000), Tenerife (2002), Paris (2004), Cambridge (2006), Bonn (2008), Shanghai (2010), Barcelona (2012), Lausanne (2014) and Luxembourg (2016).
The workshop focused on the most recent developments in the field of electronic structure methods from the first-principles perspective, their diverse applications and mathematical foundations. The numerous approaches that are developed and used in the electronic-structure community provide the foundation for computing many physical and chemical properties of solids, liquids, and low-dimensional systems. However, there are numerous challenging applications for which the level of approximation is insufficient or where computational costs are prohibitive for accurate quantitative prediction of material properties. Therefore, continued efforts are devoted to an improvement of existing methods and the development of new methods.
10-12 January 2018, Paris, Institut Henri Poincaré
Francois Bottin (CEA-DIF, France)
Johann Bouchet (CEA-DIF, France)
Matthieu Verstraete (University of Liege, Belgium)
Olle Hellman (California Institute of Technology (Caltech, US)
The quantitative prediction of harmonic phonon frequencies and thermodynamical quantities is one of the great successes of atomistic electronic structure in the past 30 years. Reality is however more complex, and vibrations are never purely harmonic. The systematic calculation of all possible anharmonic processes is a daunting task. Anharmonicity influences many important phenomena such as thermal expansion and Fourier’s law or coherent phonon generation. Heat transport is a central pillar of solid state physics and engineering, and influences many devices and properties. Both low and high conductivity materials have their uses, but historically its control has proved elusive. Simple mechanistic (grind it up) or back of the envelope (make it heavy) models reached their limits years ago. But only in the past 10-15 years a full chemically specific and atomistic prediction of lattice thermal properties has become possible. The field has blossomed at the crossroads of Chemistry, Physics, Engineerings (Energy, Mechanical, Electronic etc…), and benefitted from a positive feedback loop
through refined experiments and novel theories.
The aim of this workshop is to bring together cutting edge researchers in the numerical simulation and experimental determination of anharmonic phonon dynamics, and related properties (transport, ultrafast, electrons), to foster new approaches, new ideas, and give the field a decisive kick forward. We anticipate intense discussions and hotly contested debate about
where to go from here, as the terrain is wide open.
The series of ADIS workshops is inspired by the impressive variety of competing mechanisms on the microscopic/atomic scale, which determine the performance of engineering materials such as steels. Accordingly, the main scope of the workshops is a thorough and detailed discussion of this behavior, in order to understand the underlying physics and to contribute to a further systematic improvement of the materials. We are convinced that a truly predictive approach to materials modeling needs to be based on a fundamental ab initio level, rooted in the laws of nature rather than empiricism. This is also the driving force for the collaborative research centre SFB761 Steel ab initio, which is devoted to a quantum-mechanically guided design in high- and medium-Mn steels and funding this workshop. We are grateful that the importance of this development is further recognized by the Psi-k Charity, which is financially supporting ADIS2016. Continue reading International Workshop on Ab initio Description of Iron and Steel: Mechanical Properties (ADIS2016)→
-Maurizia Palummo, Physics Department Tor Vergata University, Rome, Italy
-Giacomo Giorgi, Department of Civil & Environmental Engineering (DICA) University of Perugia, Italy
-Jeffrey Grossman, Materials Science Department MIT, Boston, USA
Isolating graphene for the first time in 2004, with its plethora of possible device⎯oriented appealing features, has paved the way towards the study of several new classes of layered two-dimensional (2D) materials. In several opto-electronic applications such as those involving the solar-to energy conversion process, it is indeed extremely appealing to control the properties of well-understood 3D materials by reducing their dimensionality towards the 2D limit or, even better, to directly focus on naturally layered materials both free⎯standing and also coupled with other layered ones in order to boost the sunlight conversion efficiency. Moreover, stacked Van der Waals (vdW) heterostructures of 2D monolayers offer a unique playground to engineer the opto⎯electronic properties towards the realization of devices with different functionalities and with the availability of metallic, semiconducting, and insulating materials.Due to their high surface to volume/ratio 2D⎯layered materials can harvest solar energy and generate electrons and holes, and they can also provide paths for the separation and diffusion of the photo-excited carriers. These are fundamental prerequisites for the realization of any photo⎯catalytic or photovoltaic cell.The use of these emerging two-dimensional layered materials in technological applications presupposes a detailed knowledge of their chemical and physical properties. Theoretical methods and simulations play a fundamental role for the understanding and predicting these properties.The goal of the workshop, collecting distinguished scientists in the field, has been to clarify the theoretical microscopic understanding of layered 2D Materials with a particular focus on applications in opto-electronics and solar⎯to⎯energy conversion.An overview of the research at experimental level from experts in the field has also been given.Continue reading scientific report on the Psi-k workshop “2D layered materials for opto-electronics: a theoretical/computational perspective”→
Organizers: Thomas Frauenheim (University of Bremen, Germany)
Oleg Prezhdo (University of Southern California, Los Angeles, US)
Christoph Lienau (University of Oldenburg, Germany)
Chiyung Yam (Computational Science Research Center, Beijing, China)
Location: University of Bremen, Germany,
9th until 13th of October 2017
Advances of time-resolved experimental techniques, needed for a detailed understanding of charge carrier dynamics as they occur in real time, require matching progress in theoretical approaches. Applications to novel, emerging nanoscale materials, which ultimately lead to faster, more efficient and miniaturized devices, pose multiple theoretical challenges. Modeling time-resolved experimental data becomes a major goal of a theorist.
The proposed workshop became a forum to brainstorm ideas about solutions to important computational problems, and identify new directions for time-dependant electronic structure method development and challenging applications. In this way, we have been able to create an exchange mechanism to unite a core of developers in an interactive environment, in order to initiate design of a new generation software tools for quantum modelling of realistic complex systems and nanostructures in electronic ground and excited states. The delivery of this technology to a broad community will facilitate breakthroughs on high-impact materials science problems. Continue reading Scientific report regarding the CECAM Workshop: “Charge carrier dynamics in nanostructures: optoelectronic and photo-stimulated processes”→
Interface Morphology Prediction with Robust and Efficient Structure Search (IMPRESS)
Aalto University, Finland, 7-9 June 2017
Organisers: Dr Milica Todorović (Aalto University, Finland), Dr Oliver T. Hofmann (Technical University of Graz, Austria), Prof. Patrick Rinke (Aalto University, Finland)
Funding: CECAM, Psi-K, NOMAD CoE, Aalto University CMMP doctoral network
Determining or predicting the structure of organic ensembles on surfaces is a challenging problem that occupies basic science and engineering alike. Recently, novel machine-learning approaches have started to compete with more traditional, stochastic methods, such as basin hoping or simulated annealing. In IMPRESS, we took an interdisciplinary stance and brought together assorted experts to focus on the challenges of organic/inorganic interfaces: this is the first workshop to unite different electronic structure methods, structure search approaches and machine learning.
CECAM-HQ-EPFL, Lausanne, Switzerland, 26-29 September 2017
Organizers: Carlos L. Benavides-Riveros (Martin-Luther Universität Halle-Wittenberg, Germany), E. K. U. Gross (Max Planck Institute of Microstructure Physics, Germany), Miguel A. L. Marques (Martin-Luther Universität Halle-Wittenberg, Germany), and Christian Schilling (University of Oxford, United Kingdom).
Sponsors: CECAM, Psi-k and Max Planck Institute of Microstructure Physics.
This international workshop discussed and explored new aspects and challenges in Reduced Density Matrix Functional Theory (RDMFT). The main aim was to bring together leading experts in the field to address and carefully discuss open challenges in RDMFT such as implementations of 1-particle symmetries, extensions to open-shell atoms and molecules, time-evolution, temperature dependency and new insights about RDMFT from recent progress on the 1- and 2-body N-representability problems and density matrix renormalization group. The list of speakers was carefully chosen to include experts in various disciplines required for the accomplishment of the proposed scientific program. To maximize the success of the workshop, we asked all speakers to provide rather informal and interactive presentations. We also asked them to share their slides and other supplemental materials with all the participants in advance, allowing them to prepare the workshop accordingly. This ‘homework’ enabled not only fruitful and stimulating scientific discussions, but also more involved questions.Continue reading Scientific report of the international workshop on ‘New challenges in Reduced Density Matrix Functional Theory: Symmetries, time-evolution and entanglement’→
Location: Abdus Salam International Centre for Theoretical Physics, Trieste (Italy), 3-7 July 2017
Organizers: David M. Ceperley (University of Illinois at Urbana-Champaign); Michele Ceriotti (Ecole Polytechnique Fédérale de Lausanne); Thomas E. Markland (Stanford University).
Local Organizers: Ali Hassanali (The Abdus Salam International Centre for Theoretical Physics); Sebastiano Pilati (University of Padova).
The main goal of this interdisciplinary workshop was to gather together physicists and chemists who employ computer-simulation methods based on path integrals to investigate different systems, ranging from chemical and biochemical compounds, to quantum fluids/solids, to ultracold gases. This event allowed a broad community of researchers to create a platform for exchanging knowledge and know-how on path-integral technology and on other approaches to the combined quantum simulation of electrons and nuclei. Furthermore, speakers had the opportunity to showcase the most recent applications to various intriguing quantum phenomena, including, e.g., isotope effects in aqueous systems, quantum fluctuations in enzyme catalysis, quantum phase transitions due to strong correlations, and tunnelling phenomena in molecular systems and in adiabatic quantum computers (alias quantum annealers), thus creating a new bridge between quantum chemistry and quantum computing.
This event took place at the ICTP Adriatico Guesthouse, in a warm and sunny Trieste, allowing participants to enjoy the view of the Adriatic sea and the Miramare park. The format included 24 (long) oral presentations given by invited speakers, 7 short talks selected from contributed abstracts, 21 flash presentations (meant to advertise the content of a poster), and a total of 24 poster presentations. The workshop was attended by a total of 80 participants (including directors and speakers) from 29 countries.
This event has been sponsored by ICTP and by the Psi-k Network.
Psi-k workshop on
“Atomic scale materials microscopy: theory meets experiment”
National Railway Museum, York (UK)
26-28 June 2017
Atomic scale materials characterization is now one of the major drivers of technological innovation in areas such as nanoelectronics, catalysis, medicine, clean energy generation and energy storage. This can in a large part be attributed to advances in electron and scanning probe microscopies, which are now able to provide atomically resolved structural, chemical and electronic characterization of a wide range of functional materials. However, the types of systems relevant to applications, which include surfaces, interfaces, nanocrystals and two-dimensional materials, are complex and interpreting experimental images and spectra is often extremely challenging. On the other hand, parallel advances in theoretical approaches means that theory can often offer invaluable guidance. These approaches include first principles methods for structure prediction, simulation of scanning probe and electron microscopy images, and prediction of various spectroscopic signatures (e.g. EELS and STS). Some of the most impressive examples of this kind of research in recent years have combined complementary theoretical and experimental approaches in a synergistic way to unravel the complex structure of materials. This type of integrated approach is increasingly being recognised as critical to advanced materials research and development by both industry and research funders.
It was in this context that the Psi-k workshop: “Atomic scale materials microscopy: theory meets experiment” was held between the 26th and 28th of June 2017 at the National Railway Museum in York (UK). The scientific focus was on the application and development of first principles methods that, in synergy with advanced microscopy techniques (e.g. TEM, EELS, STM, AFM), can help to unravel the structure and properties of materials at the atomic scale. Open to both experts and newcomers the aim was to provide a rounded overview of emerging methods and challenges in the field, and provide an opportunity for in-depth discussion and exchange of ideas. Continue reading SCIENTIFIC REPORT ON THE PSI-K WORKSHOP: “ATOMIC SCALE MATERIALS MICROSCOPY: THEORY MEETS EXPERIMENT”→
Ab initio (from electronic structure) calculation of complex processes in materials