The Psi-k Community

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.

Psi-k is a bottom-up researchers’ network, established in 1994, to build strength and cooperation in the field of computational electronic structure. Psi-k activities are coordinated by a Board of Trustees, a Scientific Advisory Committee, and 16 Working Groups. These activities encompass the organization or co-sponsoring of ~30 workshops, conferences, schools or tutorials every year, an annual research conference jointly with CECAM, and a major conference covering the entire field every 5 years.

In addition, Psi-k produces a regular newsletter with extensive scientific highlights, and allows researchers to advertise job openings, events, and other topics of mutual interest through its 5000+ members mailing list.

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.

Psi-k is a registered charity and can only continue to operate thanks to the contributions from our member organisations and institutions. If you would like to make a donation to Psi-k please contact us to request an invoice or make a donation directly through our PayPal account…


Psi-k 2025 Conference: Worldwide Community Call for Symposia

To all in the Psi-k Community,

As previously announced, the next Psi-k Conference will take place in Lausanne on 25-28 August 2025. Registration will open around the end of 2024, so please save the date for now.

This is a worldwide community call for suggestions of thematic symposia (including their invited speakers and organisers) for the Conference.

As many of you know, Psi-k organises a general conference in its field every five years or so. The 2025 Conference will be the seventh in the series, following the very successful event already held in Lausanne (2022), and the earlier editions in San Sebastian (2015), Berlin (2010), and Schwäbisch Gmünd (2005, 2000, 1996). With 1200+ participants attending the last Conference, this makes it the largest event worldwide in first-principles simulations, theory, and applications.

The Conference will take place over 3.5 days, starting on the Monday afternoon, and will feature six plenary speakers. It will also include more than 120 invited and 240 contributed talks, organised into 30+ symposia in six parallel sessions. On average, symposia will last between two and three hours, and cover between two and four invited talks (30 min each), and between two and six contributed talks (15 min each).

To propose a symposium, you need to have a group of up to four organisers, as broad and as diverse as possible, identify a symposium theme (keeping in mind that about 20 symposia will be broadly dedicated to the core activities of the Psi-k working groups, and suggest between two to four invited speakers. Organisers of selected symposia will also be in charge, in May 2025, of selecting contributed talks (two to six) from among all the abstracts submitted to the symposium by Psi-k 2025 participants.

The Psi-k 2025 Program Committee will evaluate in September 2024 all the submitted suggestions – the criteria will be:
1. scientific merit, timeliness, and interest of the topic
2. intellectual diversity and inclusiveness of the speakers
3. scientific merit and diversity of the organisers
4. alignment with the Psi-k mission statement (

You can find the symposium suggestion form directly here:
The deadline for suggestions is 5 July 2024.

We are very much looking forward to a successful Psi-k 2025, and to seeing you all in Lausanne.

Peter Haynes
(Psi-k 2025 Conference Chair)

Arash Mostofi
(Psi-k Chair of Trustees)

2024 CECAM Psi-k Research Conference

Dear all,

It is a great pleasure to invite you to the upcoming joint annual conference between CECAM and Psi-k:

2024 CECAM Psi-k research conference — Electronic-structure simulations for large-scale facilities: Opportunities, challenges, and roadmaps

Tue May 28 2pm (CEST) to Fri May 31 1pm (CEST), 2024

The conference will be live-streamed to anyone interested (no registration needed). The short link to the zoom is The QR code to access is attached.

For all details, program, and application for in-person participation:

The following topics will be covered: 

  • Electrons and phonons; 
  • magnetic spectroscopies; 
  • X-ray spectroscopies; 
  • light-matter interactions; 
  • data and workflows.

Looking very much forward to this event,

Nicola Marzari (EPFL and PSI), Barbara Montanari (STFC), Leon Petit (Daresbury), Giovanni Pizzi (PSI), David Prendergast (Lawrence Berkeley), Gilberto Teobaldi (STFC) 

Report for Theoretical Spectroscopy Lectures 2024

The aim of the school was to give a comprehensive introduction to the theoretical and practical aspects of the electronic excitations  that are probed by experimental techniques such as optical  absorption, EELS and photoemission (direct or inverse). From a theoretical perspective, excitations and excited state properties are out of the reach of density-functional theory (DFT), which is a ground-state theory. Over the past three decades, alternative ab-initio theories and frameworks capable of describing electronic excitations and spectroscopy, have gained popularity including 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 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 response and real-time spectroscopies. Additionally, the school provided valuable insights from an experimental perspective on spectroscopies and magnetic excitations, rarely covered in similar events. Finally, a large part of the school was devoted to getting familiar with the codes that implement such theories (ABINIT, 2Light, Lumen, DP, and EXC). Continue reading Report for Theoretical Spectroscopy Lectures 2024

CECAM Flagship Workshop: Electronic Structure Software Development: Advancing the Modular Paradigm

CECAM Flagship Workshop: Electronic Structure Software Development: Advancing the Modular Paradigm

Held at CECAM-HQ, EPFL, Lausanne, February 19-24, 2024

This workshop continues the successful trajectory of the CECAM Electronic Structure Library initiative, aimed at supporting and connecting developers of shared libraries and software tools in support of electronic structure simulations across our entire community. As always, CECAM’s professionalism and remarkable organization, as well as their truly welcoming hospitality, deserve the highest praise.


Shared computational libraries that provide key functionality are now firmly established parts of the electronic structure software ecosystem. As electronic structure methods and codes diversify and mature, the development of libraries strengthens collaborations and avoids reimplementing the same methods in the context of a different, monolithic code. Over the years, a modular paradigm has emerged in which central pieces can be shared and reused between different projects. Continue reading CECAM Flagship Workshop: Electronic Structure Software Development: Advancing the Modular Paradigm

LOBSTER School on Chemical Bonding Analysis

The LOBSTER School on Chemical Bonding Analysis took place at Aalto University, Finland on 12-14 March 2024 and gathered over 30 participants. The purpose of the School was to introduce the theory and practicalities, as well as recent developments on both, behind the LOBSTER code. LOBSTER is a popular code that allows the user to perform “electronic structure reconstruction” in terms of localized projections of plane-wave-based wavefunctions, allowing a quantitative interpretation of the nature of chemical bonding in solids.

Continue reading LOBSTER School on Chemical Bonding Analysis

CECAM/Psi-k Flagship School on Machine Learning Interatomic Potentials for Young and Early-Career Researchers (ML-IP 2023)

Machine learning interatomic potentials (ML-IPs) have now established themselves as a key technique in atomistic modeling. They allow the simulation of many diverse types of systems, from the molecular to the solid state, at the accuracy of highly sophisticated electronic structure methods but at a greatly reduced cost. While the general methodology of training and validating a machine learning potential has been well established, many codes and integrated software applications exist to perform these tasks. Since many of these come with a high entry barrier, there is still a need to educate young and early-career researchers in these tasks, as well as provide a pathway to enter the field and make valuable contributions for researchers who have promising ideas that could benefit from the application of ML-IPs.

Continue reading CECAM/Psi-k Flagship School on Machine Learning Interatomic Potentials for Young and Early-Career Researchers (ML-IP 2023)

Quantum Monte Carlo HPC Applications in Condensed Matter, Quantum Chemistry and Materials Science 25 January 2024 | 09:30 -12:30 CET

Join us for a deep dive into the cutting edge of quantum materials research and quantum chemistry at the upcoming webinar on “Quantum Monte Carlo HPC Applications in Condensed Matter, Quantum Chemistry, and Materials Science” on January 25, 2024, from 09:30 to 12:30 CET. The webinar is a collaborative effort between the Targeting Real Chemical Accuracy at the EXascale (TREX) project and CECAM (Centre Européen de Calcul Atomique et Moléculaire).

Overview and objectives

The webinar will be exploring the frontiers of quantum materials research and quantum chemistry,  by means of Quantum Monte Carlo (QMC) calculations, owing to their unique suitability in solving complex many-body problems as well as in harnessing the parallelism offered by upcoming exascale supercomputer architectures.

The agenda covers a spectrum of key topics, including magnetism, surface physics, layered materials, energy excitations, and high-pressure hydrogen. Participants will gain a deeper insight into high-performance computing applications via quantum Monte Carlo simulations.

Target Audience

This webinar caters for researchers, students and professionals in the fields of quantum chemistry, condensed matter physics, and materials science.


Theoretical Spectroscopy Lectures :: Cecam School March 2024

dear colleagues and friends,
it is with pleasure that we announce the forthcoming

Theoretical Spectroscopy Lectures

that are going to take place in CECAM, Lausanne
March 11, 2024 – March 15, 2024.

The deadline for registering is 5 February 2024.

The event is going to take place at the CECAM HQ in Lausanne. Please take note that in order to participate to the hands-on sessions, you are required to come with a laptop (better if running under Linux).

Please find here the details of the school

We thank Psi-k and the gdr REST for extra funding.

Looking forward to seeing you in Lausanne.

The organisers,

Francesco Sottile
Gian-Marco Rignanese
Valerio Olevano

Ab initio (from electronic structure) calculation of complex processes in materials