Click here to read a brief, personal and unofficial account of the first 25 years of the Psi-k Network, written by members of the Band Theory Group at STFC Daresbury Laboratory. This is a record of the authors own recollections, particularly of events in the early days, and of the subsequent evolution of the Network as the scientific field itself evolved technically and intellectually. It is important to note that this is a record of how the authors saw things; it is in no way intended to be an “authorized history” of Psi-k.
From 27th to 31th January 2020 the YAMBO school devoted to first-principles calculations of electronic excited state properties in Novel Materials was held at the Abdus Salam International Center for Theoretical Physics on the Miramare seafront in Trieste. This school welcomed 56 participants from 22 countries, and 18 staff members among lecturers, teaching assistants, and organizers. The event was sponsored jointly by the Max Centre of Excellence Materials at Exascale, ICTP, and Psi-k network. The participants were 65% Master or PhD students and 35% postdocs. Overall participated 75% males and 25% females.
The goal of the school was to provide training on theoretical and computational methods to study the exciting properties with a particular focus on Novel Materials of interest for optoelectronics. In the morning, the students followed lectures on the fundamentals, from Density Functional Theory to linear response and many-body perturbation theory. A completely new session has been dedicated to real-time MBPT methods and simulations which are able to tackle electronic correlation beyond linear response.
The theoretical lectures were followed by technical ones on the implementation, within first principles, of the main theoretical equations, with a special focus on the Yambo code. Continue reading Computational School on Electronic Excitations in Novel Materials Using the Yambo Code
Hermes 2018 Summer school began with an inspiring introductory lecture from keynote speaker Prof. Adrian Sutton, sharing with us his exciting story of his academic work and personal journey in condensed matter physics and materials science. Prof. Sutton is a fellow of the Royal Society and one of the founders of the Thomas Young Centre for the theory and simulation of materials in London.
Prof. Sutton’s talk discussed the importance of recent developments in materials science and the potential impact of future technological materials on human life. For example, he discussed polymer/plastic technologies, how important plastics have become in our everyday lives, as well as the impact of these technologies on the environment and how we can make a difference as theoretical/computational scientists.
Following the keynote lecture, informal discussions continued over dinner in the beautiful dining halls of the Cumberland Lodge. The evening ended with an informal ice-breaking social mingle, allowing the participants to relax, explore the great Windsor Park and the lodge itself while getting to know each other.
A demanding several days awaited: a series of graduate lectures focusing on the main branches of computational materials science, a series of workshops on those topics (molecular dynamics, density functional theory and finite element modeling), and a seriesof lectures and workshops on science communication, to be put to use in the poster session and presentation competition. Continue reading Hermes 2018 Summer School in Computational Materials Science and Scientific Communication
Joint Psi-K / CECAM workshop: Ultrafast Physics from Molecules to Nanostructures
Dates: 7-10. October 2019
Location: San Sebastian, Spain
The impressive progress in ultrafast laser technology, ranging from the femtosecond to the attosecond timescale and from the THz to the XUV frequency range, is making possible to probe real-time electronic and nuclear dynamics in atoms, molecules and solids. Fundamental insight can be gained into the primary photoinduced processes in systems with growing level of complexity. The capability of following and steering ultrafast dynamics has tremendous impact in a wide range of applications, from materials science to life sciences.
Clearly, advances in theories and methods inevitably require an intense exchange with the experimental community due to the complexity of the systems and of the measurements. In the last decade the effort in developing predictive and computationally feasible methods has virtually exploded. Ab initio approaches based DFT and nonequilibrium Green’s function (NEGF) have recently made contact with time-resolved experiments in 2D systems and nanostructures. Other ab initio methods based on wavefunctions (e.g., ADCn, CASPTn) or reduced quantities (e.g., TDDFT, NEGF) are opening up high prospects to access the electron-nuclear subfemtosecond dynamics in molecules. Furthermore, accurate real-time numerical methods have been put forward for strongly correlated model systems (e.g., TD- DMFT and DMRG).
The workshop has gathered world-leading experimental, theoretical and computational experts working in the field of electronic and nuclear dynamics in atoms, molecules and solids. These four days have provided a unique cross- fertilization opportunity to advance the current ab-initio state-of-the-art approaches. Several key and crucial questions have been vividly and intensely debated: how to extend the accuracy of ab-initio methods out-of-equilibrium? How to efficiently benefit from the advances in computation facilities to simulate the nonequilibrium dynamics of large molecules, nanostructures and solids? How to translate laser-pulse features (pulse center frequency, bandwidth, duration, fluence, polarization) into boundary conditions and suitable approximations for the computational tools? Can we devise a series of tools and procedures to provide to the community? We have also confronted different theoretical formulations of experimental outcomes, discuss their range of applicability as well as their physical and numerical limitations. For the various approaches we have explored how to include the missing physics and whether this inclusion is numerically feasible.
Giulio Cerullo (PM, Milano)
Hardy Gross (MPI, Halle)
Andrea Marini (CNR, Rome)
Mauro Nisoli (PM, Milano)
Angel Rubio (MPI, Hamburg)
Gianluca Stefanucci (UTV, Rome)
Platja d’Aro, Spain, September 9 – 13, 2019
Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
Humboldt-Universität zu Berlin, Berlin, Germany
Fritz Haber Institute of the Max Planck Society, Berlin, Germany
CISPA – Helmholtz Center for Information Security, Germany
Materials science is entering an era where the growth of data from experiments and simulations is expanding beyond a level that is addressable by established scientific methods. The so-called “4 V challenge” – concerning Volume (the amount of data), Variety (the heterogeneity of form and meaning of data), Velocity (the rate at which data may change or new data arrive), and Veracity (uncertainty of quality) is clearly becoming eminent. Issues are, for example, an early discrimination between valuable and irrelevant experimental data, understanding errors in both experiment and theory, and assigning error bars and trust levels to density-functional theory high-throughput screening results, just to name a few. Most importantly, however, is that Big Data of materials science provide a significant chance for new insight and knowledge gain when fully exploiting its information by artificial intelligence concepts and methods. All the above aspects – from data processing to exploiting the potentials of data-driven materials science – require new and dedicated approaches.
The Department of Chemistry and the Thomas Young Centre at Imperial College London and the Theoretical Chemistry Group of the University of Torino, in collaboration with the Computational
Materials Science Group of the Science and Technology Facilities Council (STFC), organized the 2019 MSSC Summer School on the “ab initio modelling of crystalline and defective solids with the CRYSTAL code”.
CRYSTAL is a general-purpose program for the study of periodic solids. It uses a local basis set comprised of Gaussian type functions and can be used to perform calculations at the Hartree-Fock, density functional or global and range-separated hybrid functionals (e.g. B3LYP, HSE06), double hybrid levels of theory. Analytical first derivatives with respect to the nuclear coordinates and cell parameters and analytical derivatives, up to fourth order, with respect to an applied electric field (CPHF/CPKS) are available.
The school provided an overview of the underlying theory and fundamental issues affecting use of the code, with particular emphasis on practical issues in obtaining reliable data efficiently using modern computer hardware.
All information about the school can be found on this website:
Read the full workshop report here: MSSC2019_Psi-k_report
This event was the latest in the “mini” series associated with the “Total Energy and Force Methods” 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), Luxembourg (2016), and Cambridge (2018).
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 the improvement of existing methods, and the development of new methods.
Read the full report here:
Workshop Ab initio Modelling of Advanced Materials (AMM 2019)
10-13 September 2019, Onegin hotel, Ekaterinburg, Russia
From 10th to 13rd September 2019 the second workshop AMM2019 devoted to the recent progress in the development and application of ab-initio based methods of calculation and thermodynamic/kinetic modeling for microstructure and finite-temperature properties of a wide range of materials was held at conference hall of Onegin hotel in Ekaterinburg, Russia. This workshop welcomed 73 participants from 14 countries (including organizers), and 3 staff members. During the workshop, 25 oral talks and 14 key-note lectures were presented. The event was sponsored Psi-k organization, and the Institute of Metal Physics Ural division RAS (Ekaterinburg, Russia).
The purpose of this workshop was to brings together prominent scientists from the area of theoretical modelling to assess the state of the art in applications of the electronic structure theory for the knowledge-based design of advanced materials. Because the AMM2019 workshop was scheduled as a satellite to the international conference on magnetism EASTMAG-2019, the cooperation-promoting atmosphere of the both events were provided. The special topic of AMM2019 was related to problems of magnetism and magnetic materials. The main focus of the AMM2019 was to provide a fruitful framework for development and dissemination of novel ideas and concepts in order to resolve the present challenges in the field and development of new strategy for design of the materials by using combined multi-disciplinary efforts.
CECAM-HQ-EPFL, Lausanne, Switzerland
July 22, 2019 – July 24, 2019
CPMD meetings have a tradition stretching back two decades in bringing together a diverse mix of computational scientists working on different aspects of molecular dynamics simulations, combining
aspects of electronic structure theory and statistical sampling methods, as well as state-of-the-art applications ranging from materials science to biophysics.
This edition of the meeting – which marked the 20th anniversary of the first CPMD meeting at Ringberg Castle (Munich) – focused on identifying the most pressing challenges in the field, and on discussing the most promising directions to face such challenges. Given the growing relevance of machine-learning methods in the field of atomic-scale modelling, the topic was given a particular
focus, informed the choice of the speakers and the organization of the program.
Joint Psi-K / CECAM workshop: Electron-phonon coupling: Computational methods for electronic transport in nanostructures and in bulk materials
Dates: 14-16. October 2019
Location: USI Lugano, Switzerland
During 3 hectic days in October 2019, 25 researchers from different specialties meet in Lugano to discuss and learn about electron-phonon coupling. The purpose of the workshop was explicitly to foster collaboration between researchers in the following fields:
- Real-life performance of semiconductors and metals, whether it be in one, two, or three dimensions, is often limited by carrier scattering by phonons. The mobility of charge carriers is a key parameter in the semiconductor industry to describe the electrical performance and the movement under applied electric fields. The traditional approach to calculate phonon-limited mobility is based on the Boltzmann transport equation in combination with the effective mass approximation and empirical deformation potentials. In recent years predictive parameter-free mobility calculations have been carried out at the density functional theory (DFT) level for the electron-phonon coupling (EPC).
- EPC may also lead to a Bose-Einstein condensation of electrons near the Fermi surface as Cooper pairs, resulting in conventional superconductivity at sufficiently low temperatures or high pressures. Also here DFT calculations of EPC have explained the origin of superconductivity in a range of materials and provided quantitative estimates for the critical temperature using Migdal-Eliashberg theory. A recent example includes first-principles theory that revealed how high-pressure hydrogen sulfide is a strongly anharmonic superconductor.
- In a different context, the introduction of Inelastic Electron Tunneling Spectroscopy have opened up the possibility to study adsorbates and molecular junctions and to characterize inelastic scattering against vibrations down to the single-molecule limit. Ab-initio approaches based on DFT and nonequilibrium Green’s functions (NEGF) have been developed to describe the EPC in such nanoscale junctions and to explain the inelastic transport characteristics.