Category Archives: Reports

Theoretical Spectroscopy Lectures

October 8, 2018 to October 12, 2018
Location: CECAM-HQ-EPFL, Lausanne.

The aim of the school was to give a deep introduction on the theoretical and practical aspects of the electronic excitations, which are probed by experimental techniques such as optical absorption, EELS and photo-emission (direct or inverse). From the theory point of view, excitations and excited state properties are out of the reach of density-functional theory (DFT), which is a ground-state theory. In the last thirty years, other ab-initio theories and frameworks, which are able to describe electronic excitations and spectroscopy, have become more and more used: time-dependent density-functional theory (TDDFT) and many-body perturbation theory (MBPT) or Green’s function theory (GW approximation and Bethe-Salpeter equation BSE). In fact, computational solutions and codes have been developed in order to implement these theories and to provide tools to calculate excited state properties. The present school focused on these points, covering theoretical, practical, and also numerical aspects of TDDFT and MBPT, non-linear reponse and real-time spectroscopies. Finally, a large part of the school was devoted to the codes implementing such theories (ABINIT, 2Light, Lumen, DP, EXC).

Continue reading Theoretical Spectroscopy Lectures

23rd ETSF Workshop on Electronic Excitations: Interdisciplinary views on quantum many-body theory

The 23rd ETSF Workshop on Electronic Excitations
Interdisciplinary views on quantum many-body theory
The University of Milan, Italy, September 10 – 14, 2018

Group picture in front of Castello Sforzesco

The 2018 edition of the European Theoretical Spectroscopy Facility (ETSF) Workshop on Electronic Excitations has been dedicated at fostering the cross-fertilization between different approaches to many-body phenomena, transcending the traditional barriers between disciplines. The workshop therefore brought together experts facing similar problems from different perspectives, for different applications, and often with a different language. Besides discussing application of many-body theories to excitations in condensed matter, i.e. the traditional field of expertise of ETSF, topics covered by the workshop included nuclear physics, quantum chemistry, ultrafast excitation dynamics, quantum transport, topological insulators and novel algorithmic approaches to many-body problems inspired by machine learning and data science.

Continue reading 23rd ETSF Workshop on Electronic Excitations: Interdisciplinary views on quantum many-body theory

Scientific report on the 17th International Conference on Density-Functional Theory and its Applications

The 17th International Conference on Density-Functional Theory and its Applications (DFT2017) took place in Tällberg, Sweden, in August 2017. The conference belongs to a series of biennial meetings, which have taken place in Paris (1995), Vienna (1997), Rome (1999), Madrid (2001), Brussels (2003), Geneva (2005), Amsterdam (2007), Lyon (2009), Athens (2011), Durham (2013), Debrecen (2015) and Tällberg (2017). DFT2017 covered a wide range of topics related with density functional theory. It brought together the foremost researchers from all around the world working on the development of the theory, extensions to new fields and providing a broad range of fascinating applications.

Conference Webpage:


Prof. Dr. Levente Vitos, KTH Stockholm, Sweden


Prof. Dr. Olle Eriksson, Uppsala University, Sweden
Prof. Dr. Börje Johansson, KTH Stockholm, Sweden
Dr. Xiaoqing Li, Uppsala University, Sweden
Stephan Schönecker, KTH Stockholm, Sweden
Prof. Dr. Levente Vitos, KTH Stockholm, Sweden

International Scientific Committee:

Prof. Dr. Henry Chermette, Universite de Lyon, France
Prof. Dr. Claude A. Daul, University of Fribourg, Switzerland
Prof. Dr. Jose M. Garcia de la Vega, Universidad Autonoma de Madrid, Spain
Prof. Dr. Paul Geerlings, Vrije Universiteit Brussel, Belgium
Prof. Dr. Paola Gori-Giorgi, Vrije Universiteit Amsterdam, Netherlands
Prof. Dr. Miguel A. L. Marques, Martin-Luther-University Halle-Wittenberg, Germany
Prof. Dr. Ágnes Nagy, University of Debrecen, Hungary
Prof. Dr. Dennis R. Salahub, University of Calgary, Canada
Prof. Dr. Karlheinz Schwarz, Vienna University of Technology, Austria
Prof. Dr. David J. Tozer, University of Durham, United Kingdom
Prof. Dr. Levente Vitos, KTH Stockholm, Sweden



Description and summary:

In 2017, the broadest international meeting on DFT was organized for the first time in Scandinavia. Fifty three years passed since the fundamental theorems behind one of the most successful quantum theory of inhomogeneous electron gas were put forward. Already in its original form, DFT was suitable to explain a series of phenomena related to simple molecules and solids. It took nearly a quarter of century when it became robust enough to account for the magnetic ground state of a chunk of single crystal iron. More than a decade of future research was required in order to extend the scope of DFT to complex high-technology materials. Continue reading Scientific report on the 17th International Conference on Density-Functional Theory and its Applications

Report: CECAM/Psi-k Workshop Bremen on Crystal defects for qubits, single photon emitters and nanosensors

CECAM Qubit_Abstract book


Organizers: Adam Gali (Budapest), Thomas Frauenheim (Bremen), Jörg Wrachtrup (Stuttgart)

Venue: University of Bremen, Bremen Center for Computational Materials Science (BCCMS), Germany, 9th until 13th of July 2018

Sponsors: University of Bremen (BCCMS), Psi-k, DFG

Point defects acting as color centers in solids may realize single photon source and quantum bits that can be harnessed in quantum information processing and nanoscale sensor applications which may revolutionize the info-communication technology, biological research and therapy. The leading contender is the nitrogenvacancy center in diamond which may be considered as a robust quantum tool. Several quantum algorithms and protocols for sensing have been already demonstrated by this center. However, researchers face many materials science problems in order to maintain the favorable intrinsic properties of this color center that can be perturbed by other defects either in bulk or at the surface of diamond that is difficult to resolve because of its chemical hardness and the concurrent stability of carbon allotropes.

Recently, theory-driven search for alternative materials could identify other quantum bit candidates in technologically mature wide band gap semiconductors, particularly silicon carbide, that have been recently demonstrated in experiments. However, the knowledge about these color centers is scarce and only the tight collaboration of experimental and atomistic simulation researchers would lead to a rapid progress in the field. The proposed workshop aims at bringing together world-leading experts in all these fields to improve interdisciplinary cooperation overcoming traditional boundaries between scientific disciplines.

Conference Report: BIOMOLECTRO (BioMolecular Electronics) CECAM-PSI-K conference

(BioMolecular Electronics)

CECAM-PSI-K conference, Madrid, 27th -31st August 2018

Organizers: Linda A. Zotti, Juan Carlos Cuevas, Rubén Pérez

Venue: Universidad Autónoma de Madrid, Spain

Sponsors: PSI_K & CECAM (83%), Universidad Autónoma de Madrid (11%), IFIMAC (5%) and Catedra UAM-Fujitsu (2.5%)

BIOMOLECTRO was a very exciting event which took place this summer in Madrid. The aim of the conference was to bring together theoreticians and experimentalists working on the subject of electron transport through biomolecules such as proteins, peptides or DNA, as well as through bio-inspired devices and systems like bacterial nanowires. The conference was very successful, joining many world-leading scientists and proving that the field of biomolecular electronics is most certainly flourishing. This is thanks to the plethora of rich physical and chemical properties biomolecules have to offer (such as redox and optical functionalities as well as specific chemical recognition and self-assembly ) and to their potential to be employed in nanoscale devices.

The key merit of this conference was the unique joining of researchers from the fields of electron transport in molecular electronics, electron transfer in biology, and biosensors, and gathering their varied expertise and knowledge to produce many new ideas and directions. Please see below for the list of speakers and titles of their talks as well as the abstract book. Continue reading Conference Report: BIOMOLECTRO (BioMolecular Electronics) CECAM-PSI-K conference


July 10, 2017 to July 21, 2017
Abdus Salam International Centre for Theoretical Pysics, Trieste

LIST OF PARTICIPANTS (reference code or initiative in parentheses)
Volker Blum (ELSI), Viktor Yu (ELSI), William Huhn (ELSI), David Lopez (Siesta), Yann Pouillon (Abinit), Micael Oliveira (Octopus & Abinit), Fabiano Corsetti (Siesta & Onetep), Paolo Giannozzi (QE), Anoop Chandran (QE), Pietro Delugas (QE), Ivan Carnimeo (QE), Emine Kucukbenli (QE), Layla Martin-Samos (QE), Stefano de Gironcoli (QE), Ivan Girotto (QE).

First Two Days: round table presentations and discussions focusing on an analysis of the available ESL “utility tools” and on opportunities for code reuse.
From Day Three: daily morning update of the work done and planning the activity for the day. Coding sessions.

In the past several decades Electronic Structure methods have mostly been developed in self contained monolithic software distributions implementing a variety of features. Currently most of these large codes contain routines with overlapping functionality and make use of non-standard data formats due to historical reasons, and as the state of the art in theory and computer hardware progresses, the complexity of these codes continue to grow separately, in a way that reduces their inter-operability with each new version. Continue reading ELECTRONIC STRUCTURE LIBRARY CODING WORKSHOP: DRIVERS

8th School and Workshop on Time-Dependent Density-Functional Theory: Prospects and Applications

August 20th-31st, 2018
Benasque Center for Science “Pedro Pascual”, Benasque, Spain

Organizers: Angel Rubio, Eberhard K. U. Gross, Miguel A. L. Marques, Neepa Maitra, Alberto Castro

There are many alternative schemes to approach the time-dependent, out-of-equilibrium, many-electron problem. Time-dependent density-functional theory (TDDFT) has a significant “market share” due to the same reasons that make conventional ground state density-functional theory (DFT) a successful scheme: the fairly good predictive power at a moderate computational cost. As a consequence, its use has quickly grown, and its reliability for many purposes has been sanctioned by many applications and benchmarks over the years. As the computational resources increase, however, various alternatives such as advanced post-Hartree Fock multi-configuration schemes or many-body perturbation theory techniques can be applied to larger systems, and may provide more precise results. Newer and more intriguing possibilities, such as the direct solution of the many-electron Schrödinger equation with quantum computers, and the use of machine learning techniques for the prediction of many properties, appear also in the horizon. It is therefore necessary to review the capabilities and perspectives of TDDFT. This is the main goal of the Workshop, and of the School that we organized immediately before the Workshop.

This School+Workshop event is in fact a new iteration of a series dedicated to TDDFT, that started in 2004. It takes place every two years, a periodicity that we feel that is adequate to follow the advances in the topic. However, it always takes place in Europe, and there was a strong demand for a similar event taking place in the US, due to the difficulties in the travel, specially for students and young researchers. Fortunately, the demand was met in the last year by a similar event (a school on TDDFT followed by a workshop on first principles approaches to the electronic excited states problem) that took place in Telluride, Colorado. Part of the organizers of this event were also present in Benasque, and the goal is to periodically repeat the US event, also every two years if possible. It should be noted, also, that a similar event is being planned in Asia (Tsukuba, Japan), by Prof. K. Yabana.

You can read the full workshop report here.

Photoinduced Processes in Embedded Systems (PPES)

Organizers: Claudia Filippi (University of Twente, The Netherlands),  Filippo Lipparini (University of Pisa, Italy), Benedetta Mennucci (University of Pisa, Italy)

The scientific aim of the Psi-k workshop “Photoinduced Processes in Embedded Systems” was to bring together researchers from the physics, chemistry, and biophysics communities working on the computational study of photo-physical processes in complex systems. Modelling such phenomena is challenging since they involve very different space and time scales, from the extremely fast, localized absorption of light to the collective, slow motions of the environment.

The workshop has focused on some of the most recent theoretical and algorithmic developments in the field such as:

  • DFT embedding for excited states
  • Hybrid QM/Classical approaches
  • Highly-correlated methods for excited-state dynamics
  • TDDFT outside the Franck-Condon region
  • Non-adiabatic dynamics

These methodological aspects have been framed in the context of realistic applications to materials and biosystems such as:

  • Natural photosynthetic systems
  • Photo-induced signal transduction in bio-systems
  • Bio-mimetic light-driven molecular devices
  • Photo-induced charge propagation in solar-energy devices

You can read the full workshop report here.

Emergence of surface and interface structure from friction, fracture and deformation

The workshop on Emergence of surface and interface structure from friction, fracture and deformation , held at CECAM HQ in Lausanne from 24-27th July 2018, considered the topographic, morphological and chemical structure of surfaces and interfaces that arises from mechanical processes and how this structure affect the mechanical behaviour of materials but cannot typically be systematically controlled. As well as Psi-k, the workshop received support from CECAM, the DFG and EPSRC.

You can read the full workshop report here.

8th International ABINIT Developer Workshop

Initiated in 2002, the series of ABINIT developer workshops are organized every two years (Louvain-la-Neuve 2002, Paris 2004, Liège 2007, Autrans 2009, Han-sur-Lesse 2011, Dinard 2013, Liège 2015) and plays an important role in the life of the ABINIT community. It is the occasion for the most active ABINIT developers — as well as a few expert users — and selected invitees, to gather and exchange information, and present recent developments. The future of ABINIT is also discussed, and recommendations are issued.

The workshop in Fréjus followed the spirit of preceding workshops and was particularly fruitful. This year, the number of participants reached 39 people. Workshop program, abstract and oral presentations (pdf) are permanently available on the website of the conference ( linked from
ABINIT website.

You can read the full workshop report here.