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…


Defects in solids for quantum technologies – 2024

From 10th to 14th June 2024 the second conference devoted to first-principles calculations of defect qubits’ magneto-optical and spin properties for quantum technologies was held at the Eötvös Loránd University (ELTE) in Budapest, Hungary where theory also met experiments to discuss scientific issues.

This conference welcomed 154 participants from 28 countries registered for the workshop from 5 continents including the organizers. The participants showed up in person at the workshop site and attended the scientific talks except for one attendee with on-line participation. The final scientific program of the workshop lasted for five full days, included 18 invited talks, 41 contributing talks, and a poster session with 87 posters, and a Discussion session about single defect engineering with leading experimentalists and theorist. The event was sponsored jointly by the Psi-k organization, CECAM HQ, Eötvös Loránd University (Budapest, Hungary), Quantum Information National Laboratory of Hungary, and the Applied Physics Letters.

The purpose of this conference to bring together world-leading theoreticians and experimentalists active in the field of quantum information processing based on solid state qubits. Our discussions improve interdisciplinary cooperation overcoming traditional boundaries between scientific disciplines. Invited speakers at DSQT2024 workshop represented electronic structure theory community, theory at phenomenological and atomic scale level, materials growth, defect engineering, surface chemistry, quantum optics and spin physics. Recognized leaders in the field, highlighted recent progress and discuss challenges and opportunities in their invited talks. Invited talks, contributed talks, posters, and the Discussion session stimulated the exchange of methodological expertise and new developments between scientists working on different aspects of the field, illuminate opportunities for optimizing the materials properties and device design aided by theory.

The conference was originally designed to host 100 participants, but given the unexpectedly high level of requests for participation an effort was made to increase numbers and accommodate 150+ participants.

Detailed Program

Monday June 10th 2024 – Day 1

  • 08:00 to 09:20 – Registration
  • 09:20 to 10:00 – Registration + Introduction

Theory for scaling up: searching and characterization

  • 10:00 to 10:40 – Volker Blum – Dopants and compensating defects in hybrid perovskites from hybrid DFT – in supercell models with thousands of atoms
  • 10:40 to 11:00 – Coffee break

Theory: screening and excited states

  • 12:00 to 13:40 – Lunch

Color center in 2D materials

  • 13:40 to 14:20 – Hannah L. Stern – A quantum coherent spin in a two-dimensional material at room temperature
  • 15:00 to 15:20 – Coffee break

Diamond NV: novel control schemes

  • 16:40 to 18:40 – Welcome reception

Tuesday June 11th 2024 – Day 2

Silicon carbide qubits I

  • 09:40 to 10:20 – Jörg Wrachtrup – TBA
  • 10:40 to 11:00 – Coffee break

Silicon carbide qubits II

  • 12:00 to 13:40 – Lunch

Diamond NV center: electrical control

  • 15:00 to 15:20 – Coffee break

Diamond NV center for quantum sensing

  • 16:40 to 18:40 – Poster session: SiC, diamond NV quantum simulation and computing, diamond alternative color center formation, Si and alternative 3D materials

Wednesday June 12th 2024 – Day 3

Theory of excited states in periodic models I

  • 09:40 to 10:20 – Cyrus E. Dreyer – Embedding methods for quantum defects
  • 10:40 to 11:00 – Coffee break

Color centers in silicon

  • 11:00 to 11:40 – Anaïs Dréau – Rotation of the center-of-mass of single G centers in silicon-on-insulator
  • 12:00 to 13:40 – Lunch

Diamond NV center: quantum simulation and sensing

  • 13:40 to 14:20 – Fedor Jelezko – Quantum simulation in isotopically engineered diamond
  • 14:20 to 15:00 – Aparatija Singha – Quantum sensing with single spin sensitivity
  • 15:00 to 15:20 – Coffee break

Color centers in diamond I

  • 16:40 to 18:40 – Discussion section
  • 19:00 to 22:30 – Cruising and dinner on Danube

Thursday June 13th 2024 – Day 4

Rare-earth ions and color centers in Si

  • 10:40 to 11:00 – Coffee break

Search for qubits in 3D and 2D materials

  • 11:00 to 11:40 – Kristian Thygesen – High-throughput discovery of quantum defects in low dimensional crystals
  • 12:00 to 13:40 – Lunch

Theory of 2D materials

  • 14:20 to 15:00 – Sivan Refaely-Abramson – Excited-State Phenomena at Defects in 2D Semiconductors: a Many-Body Perspective
  • 15:00 to 15:20 – Coffee break

Silicon carbide qubits III

  • 16:40 to 18:40 – Poster session: Theoretical methods, diamond NV sensing, alternative diamond color centers, 2D materials

Friday June 14th 2024 – Day 5

Theory of excited states in periodic models II

  • 10:40 to 11:00 – Coffee break

Color centers in diamond II

  • 12:00 to 13:40 – Lunch

Color centers in hexagonal boron nitride I

  • 15:00 to 15:20 – Coffee break

Color centers in hexagonal boron nitride II

  • 16:20 to 16:40 – Closing Word


Invited speakers



Kristian Sommer Thygesen (DTU)


Anton Pershin (Wigner Research Centre for Physics)


Sivan Refaely-Abramson (Weizmann Institute of Science)


Marco Govoni (University of Modena and Reggio Emilia)

Oscar Bulancea-Lindvall (Linköping University)


Volker Blum (Duke University)

Liang Tan (LBNL)

David Strubbe (University of California, Merced)

Cyrus E. Dreyer (Stony Brook University)




Michael Trupke (Austrian Academy of Sciences)


Patrice Bertet (University of Paris-Saclay)

Anaïs Dréau (Université de Montpellier)


Jörg Wrachtrup (University of Stuttgart)

Fedor Jelezko (University of Ulm)

Andreas Reiserer (Technische Universität München)

Aparatija Singha (Max Planck Institute, Stuttgart)

United Kingdom

Hannah L. Stern (Cambridge University)

Cristian Bonato (Heriot-Watt University)


Burcu Ozden (Penn State Abington)



The organizers of the conference were:

  • Adam Gali (HUN-REN Wigner Research Centre for Physics/Budapest University of Technology and Economics)
  • Viktor Ivády (Eötvös Loránd University)
  • Igor Abrikosov (Linkoping University)
  • Nathalie P. De Leon (Princeton University)
  • Yuan Ping (University of Wisconsin-Madison)


General remarks and feedback from participants

We found sponsors to finance the “Best poster award” that were given to a youth male scientist and a female scientist to maximize the inclusivity in both career stage and gender. We believe that we could indeed inspire the young generation of scientists by the award. Furthermore, contributed talks from early career stage scientists were given and we had a very positive feedback from these scientists in social media after the conference (e.g., LinkedIn posts). We had 5 female invited speakers to encourage youth female scientists of the audience in their career. Although, the workshop was planned exclusively in person but we offered to one female invited scientist to present her results on-line because of the difficulties to travel with her recently born baby. In the organization and local organization teams we have women and men with diverse cultural background to run the conference in order to secure an inclusive environment for people with any gender or geographical locations of various habits.

Conclusions and prospects

This conference was very successful on all fronts: the number of applicants exceeded our expectations, all lecturers did a wonderful job in preparing and delivering carefully-prepared lectures, and participants responded very positively and contributed with their energy and enthusiasm to make the best of this conference. Discussions amongst the attendees of the conferences highlighted the interest in not only continuing DSQT in its current form but also the idea of holding more specific workshops that focus on different topics within the area of ‘defects for quantum technology’. One idea that was discussed is a meeting focused on defects in two-dimensional materials, or a meeting that would include the community of those working on molecular spins for quantum technology. This could include not only the traditional electron paramagnetic resonance community interested in inorganic high spin complexes, but also the organic molecular community where the photophysics of optically addressable spins resembles that of defects in wide bandgap solids. By combining the two fields (molecular spins and solid-state defects) we would hope to broaden the theoretical and experimental approach to studying these systems. Separately, grant proposals and collaborations were discussed by participants at the meeting forming European/UK consortia.

This event would not have been possible without the impeccable local organization team from ELTE and generous support of Eötvös Loránd University (ELTE). In particular, Viktor Ivády’s team provided a great service to run the conference smoothly.

Given the very enthusiastic response of participants and lecturers alike, it will make sense to reiterate this event biannually to advance this rapidly evolving field.


Further details

Event website, with program, list of participants and abstracts

ETSF-Young Researchers’ Meeting 2024 (YRM)

27-31 May 2024, Toulouse, France 


From the 27th to the 31st of May at the University of Paul Sabatier III in Toulouse, France, the ETSF-YRM workshop was held. In particular the newly built Fermi Building hosted the event in the heart of the university complex. The event gathered 51 people from all over Europe. The event was sponsored by the Psi-K organization, NanoX and the CECAM nodes of Toulouse and Grenoble.

The objective of this meeting is to provide young researchers with the opportunity to share their work and acquaint themselves with state-of-the-art theoretical methods applied both in their own field and in others. Moreover, it offers scientists at the beginning of their careers the chance to network with young colleagues from different institutions, exchange knowledge and ideas and thus integrate further into the scientific community. The event was thought to be welcoming and inclusive, and an enriching experience for young researchers who may not have participated in many conferences before. The aim was also to provide a less intimidating setting than a large-scale international conference. In order to achieve all the above, the organizers provided a friendly and comfortable atmosphere and prioritized the early stage researchers in the oral sessions, helping them develop their presentation skills. The organization committee made sure that all applicants had equal opportunities. The YRM 2024 was divided into five oral sessions. The first session was on advanced electronic structure methods with a particular focus on spectroscopic properties. The second session was  on optical properties of materials. The third session was on the vibrational properties of materials. The fourth session was on strongly correlated systems and the fifth session was focused on machine learning in condensed matter. For each session, one or two invited speakers gave an overview of the state-of-the-art in their field and presented their work as well in a keynote talk. 

The workshop also organized a poster session and a social dinner for participants to get to know each other and discuss their current research projects.

Detailed program and book of abstracts

1.Detailed program

2.Book of abstracts


  1. Ammar Abdallah (LCPQ, Université Toulouse III )
  2. Biancorosso Leonardo (University of Trieste)
  3. Canola Sofia (Institute of Physics of the Czech Academy of Sciences)
  4. Saravanabavan Karthikeyan (CEA-Liten, University of Grenoble)

Invited speakers 

  1. Castellano Aloïs (University of Liège)
  2. Filip Maria-Andreea (Max Planck Institute for solid state research)
  3. Giarrusso Sara (University of Paris-Saclay)
  4. Janke Svenja M. (University of Warwick)
  5. Levi Gianluca (University of Iceland)
  6. Mejuto-Zaera Carlos (International School for Advanced Studies, SISSA)
  7. Nys Jannes (École Polytechnique Fédérale de Lausanne)
  8. Schaefer Julia M. (Heliatek GmbH)
  9. Urquiza Laura (École Polytechnique)
  10. Vanzan Mirko (University of Milano)

General remarks

Overall, the sessions offered a comprehensive overview of advancements in theoretical spectroscopy. The participants showcased new methodological approaches in materials and molecular sciences, including theoretical models, computational methods, and applications of artificial intelligence, alongside improvements in existing techniques. Additionally, spectroscopic properties such as optical and vibrational characteristics were discussed for novel systems of interest, including solids, molecules, and hybrids.

As experimental research in the field advances and the precision of descriptive models improves, the primary constraint remains computational feasibility. This highlights ongoing questions about how to simulate increasingly complex and large-scale systems for more accurate interpretations of experimental results.

Conclusion and prospects

The workshop was very succesfull and entartaining . All the invited speakers excelled in crafting and presenting their work. The participants responded with great enthusiasm and energy, significantly contributing to the success of this workshop. We gratefully thank Amandine Laurient who works at LCPQ in Toulouse, without her there wouldn’t be any workshop.

Interdisciplinary workshop on Theory around XFELs, November 18th to 20th in Marseille

Dear colleagues,

We are pleased to announce that the interdisciplinary workshop Theory around XFEL will take place from November 18th to 20th in Marseille.

It will gather theoreticians and experimentalists with physics, chemistry and biology backgrounds to discuss the state-of-the-art,
future prospects and opportunities of theoretical simulations related to X-ray free electron lasers. Various topics related to XFEL will be covered:

High density of energy, Structural biology, Condensed matter physics, Atoms and molecules in dilute phase, Ultrafast (atto/femto) processes.

The list of invited speakers, as well as all practical information can be found on our website:
Registration is free but mandatory. It includes lunches and coffee breaks during the workshop.
Please fill out this form:

The number of participants is limited
so please register as soon as possible.

Note that you can send an abstract if you want to be considered for an oral contribution. You will find a template on the registration form, please use this template to submit your abstract in PDF format.
Two types of contributions will be possible: regular talks of 30 minutes (questions included), and flash talks of 5 minutes. Please select which type of contribution you want when filling the registration form.
We also announce that the plenary meeting of the GDR XFEL will take place at the same location from 21th to 22th of November.

More information will soon be available here:

Don’t hesitate to contact us at [email protected] if you have any questions.
We hope to see you in Marseille next November!

The organizers
Miquel Huix-Rotllant and Marie Labeye

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

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