The Psi-k Community

Psi-k is a wide network of European researchers — working closely with many friends and colleagues around the world – that is intended to help build cooperation in the field of computational electronic structure calculations, in particular for crystalline quantum systems whose wave function Ψ has an associated wave vector k defining its periodicity, hence the name.  It is co-ordinated by a series of working groups from around Europe. It produces a monthly newsletter, organizes a major conference every five years, and allows researchers to email each other regarding job openings, events, and other topics of mutual interest. The network is also able to provide some degree of financial support for small workshops and schools, and for collaborative research visits.

MISSION: Psi-k is a Europe-based, worldwide network of researchers working on the advancement of first-principles computational materials science. Its mission is to develop fundamental theory, algorithms, and computer codes in order to understand, predict, and design materials properties and functions. Theoretical condensed matter physics, quantum chemistry, thermodynamics, and statistical mechanics form its scientific core. Applications encompass inorganic, organic and bio-materials, and cover a whole range of diverse scientific, engineering, and industrial endeavours. Key activities of Psi-k are the organization of conferences, workshops, tutorials and training schools as well as the dissemination of scientific thinking in society.

This new website — introduced in  2015 to replace a venerable old site that provided sterling service over many years — offers a much more flexible modern design and functionality and it is to be hoped that it will provide even more stimulus for collaboration and cooperation amongst its members. Instructions regarding how to use it are here.

International Workshop on Ab initio Description of Iron and Steel: Mechanical Properties (ADIS2016)

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)

scientific report on the Psi-k workshop “2D layered materials for opto-electronics: a theoretical/computational perspective”

                                       Rome, Italy, 18-19 December 2017


-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

Funding:  Psi-K


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”

Scientific report regarding the CECAM Workshop: “Charge carrier dynamics in nanostructures: optoelectronic and photo-stimulated processes”

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

  1. State-of-the-Art Summary

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”

Scientific report on the CECAM/Psi-K workshop on “Quantum-chemistry methods for materials science”

CECAM-HQ-EPFL, Lausanne, Switzerland, 08-10 November 2017

OrganizersIgor Ying Zhang and Matthias Scheffler (Fritz Haber Institute of the Max Planck Society (FHI), Berlin, Germany).

Sponsors:  CECAM, Psi-k and Fritz Haber Institute of the Max Planck Society (FHI), Berlin, Germany.


The workshop “Quantum-chemistry methods for materials science” was held at Lausanne, Switzerland from Nov 08th to 10th 2017. In total, 22 participants from Europe, USA, and China attended the workshop. The workshop stimulated an interdisciplinary exchange of ideas and knowledge about the development of advanced electronic-structure methods transferring from chemistry, solid-state physics, and materials science.
Continue reading Scientific report on the CECAM/Psi-K workshop on “Quantum-chemistry methods for materials science”

Scientific report on the “Interface Morphology Prediction with Robust and Efficient Structure Search” (IMPRESS) Workshop

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.

Continue reading Scientific report on the “Interface Morphology Prediction with Robust and Efficient Structure Search” (IMPRESS) Workshop

Psi-k Volker Heine Young Investigator Award 2018

“For research excellence in all fields involving electronic structure calculations”

Young computational science researchers are invited to put themselves forward for the Psi-k Volker Heine Young Investigator Award 2018.  The finalists will compete at a special session of the joint EPS Condensed Matter Division and German Physical Society (CMD/DPG) Spring Meeting in Berlin, during March 11-16, 2018.

The Volker Heine Award session will be part of the Symposium:
Frontiers of Electronic Structure Theory: Correlated Electron Materials

Purpose: The purpose of the Psi-k Volker Heine Young Investigator Award is to recognize an individual for her or his outstanding computational work in any type of condensed-matter, materials, or nanoscience research involving electronic structure calculations. In 2018 there will be one award of 2500 Euro and four runner-up prizes of 500 Euro each. The prize is sponsored by npj Computational Materials.

Regulations and Procedure:

1) Applicants may be of any nationality working anywhere in the world.

2) The applicant’s PhD certificate must not be dated more than 5 years before the first day of the joint CMD/DPG – EPS Conference (March 11, 2018). Those who have not yet completed a PhD can also apply.

3) Young investigators who wish to compete for the Psi-k Volker Heine Young Investigator Award 2018 must submit:

  • abstract (in the format of the abstracts for the conference)
  • two-page description making the case for her/his outstanding scientific contribution
  • extended CV (incl. list of publications and talks/posters)
  • evidence of satisfying the conditions of regulation (2) above.

These items must be submitted by email, as a pdf attachment, to the chairperson of Psi-k whose address is given below. It must be received not later than December 1, 2017. The abstract must also be submitted as a regular contribution to the CMD/DPG Conference.

4) The candidate must arrange for two confidential support letters to be sent directly by to the Psi-k chairperson (see below). These letters (sent by email) need to be received before December 1, 2017. One of the letters must certify that the candidate meets the requirements of regulations (2) above.

5) The Psi-k Trustees will select five finalists who will get an invitation to present their work at the CMD/DPG Conference (25 min. talk + 5 min. discussion). After these presentations, the award committee will select the award winner.

6) The award winner will receive her or his award of 2500 Euro and the four runner-up their prizes of 500 Euro each, together with a certificate, at a presentation on the Psi-k Scientific Get-Together during the conference.

Award Committee: The award committee will consist of selected invited speakers of the CMD/DPG Conference and three members of the Psi-k Trustees.

Risto Nieminen
Psi-k Chairman
[email protected]

Scientific report of the international workshop on ‘New challenges in Reduced Density Matrix Functional Theory: Symmetries, time-evolution and entanglement’

Group photo.
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).

Group photo of the Workshop on “Understanding Quantum Phenomena with Path Integrals: from Chemical Systems to Quantum Fluids and Solids”, ICTP – Trieste, July 2017



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