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.

Probing Potential-Energy Surfaces (PPES IV)

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The potential energy surface (PES) is a central quantity in the modelling of materials properties. Ab initio total energy methods like density-functional theory are increasingly used to probe the PES in order to determine not only the equilibrium configurations of particular systems, but also potential energy barriers for certain processes and/or attempt frequencies. The goal of the workshop was to discuss current issues and perspectives in the underlying theoretical concepts and methods, as well as corresponding applications in the fields of heterogeneous catalysis, crystal growth, or biophysics.

After successful meetings in 1994, 1999, and 2005, the workshop stayed within the interdisciplinary tradition of the PPES series and brought together scientists with different backgrounds, e.g. in condensed matter physics, materials science, computational physics, chemistry, and industry. Experts of the field of total-energy calculations, scientists who develop or enhance methods, and those who apply the information gained by these techniques had the possibility to exchange ideas and experiences.

A special focus of the PPES-IV workshop was on big-data-driven materials science, e.g. the Materials Encyclopedia and the development of Big-Data Analytics tools for materials science of the NOMAD Center of Excellence.

pic2PPES Continue reading Probing Potential-Energy Surfaces (PPES IV)

EUSpec Winter School on core-level spectroscopies – Fundamentals and applications of ab-initio methods in spectroscopy

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The idea that a two-week school should be held in Slovenia first emerged during the first Whole Action Meeting (WAM 2014) of COST Action EUSpec in Louvain-la-Neuve, Belgium. In compliance with the naming of other action meetings, the school was nicknamed as “EWinS”, standing for “EUSpec Winter School”. The preparations for the school started in spring 2015 and in autumn they became rather intense with many skype calls between the local organizers and Hubert Ebert (action chair), Didier Sébilleau (co-chair), Amélie Juhin as well as other members of the school international committee. The ideas on the table were many and the uncertainties on practical aspects were even more. Let us introduce the context. “EWinS” is the first two-week school organized within the framework of EUSpec. “Being the first” is already a source of concerns. “Being the first” in a small town of 6600 inhabitants in the middle of west Slovenia becomes an epic quest. Fortunately, with the help of volunteers, long and difficult budget plans, creative accommodation and transportation plans, on Monday the 1st of February all trainees were attending the first lecture given by Maria N. Piancastelli. After the coffee break Lucia Reining explained the basis of electronic excitations under a theoretical point of view.

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Continue reading EUSpec Winter School on core-level spectroscopies – Fundamentals and applications of ab-initio methods in spectroscopy

Walter Kohn

We are sad to report the recent passing of Walter Kohn, who died  Tuesday 19 April in Santa Barbara, California.

The following is his obituary from the New York Times

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Walter Kohn, an Austrian-born American scientist and former refugee who shared a Nobel Prize in Chemistry — a subject that he had last formally studied in high school — died on last Tuesday in Santa Barbara, Calif. He was 93.

The cause was cancer of the jaw, his wife, Mara Vishniac Kohn, said.

As a teenager, Dr. Kohn had escaped to England from Nazi-occupied Vienna less than a month before World War II erupted, found himself shipped to Canada as an “enemy alien” and later built a long, distinguished academic career in the United States, becoming an American citizen in 1957.

He was awarded the chemistry prize by the Royal Swedish Academy of Sciences in 1998. At the time, he was teaching at the University of California, Santa Barbara. He shared the award with John A. Pople, a British-born mathematician at Northwestern University.

Dr. Kohn was credited with a discovery that applied quantum mechanics and advanced mathematics to explain complex chemical reactions.

Continue reading Walter Kohn

Psi-k Scientific Get-Together

During the DPG Condensed Matter Meeting in Regensburg the Psi-k Network will organize again a Psi-k Scientific Get-TogetherPsi-k_Get_Together_2016_A4

We hope that you can come to the meeting and that we have a nice Get-Together. Please distribute the attached flyer to your colleagues and coworkers.

See you in Regensburg

Peter Dederichs
Honorary Chairman

Simulation of chemistry‐driven growth phenomena for metastable materials – SimGrow 2015

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The controlled growth of thin films based on metastable materials by chemistry‐driven processes is of high technological importance for topics like semiconductor devices or optical coatings. Computational modelling of this inherently multiscale process is crucial for an atomistic understanding and enables a decoupling and separate optimization of the growth‐determining factors of non‐equilibrium materials. The challenge faced for modelling of these complex phenomena is the coverage of various length and time scales and the necessary close interaction with colleagues from the experimental sciences who are able to outline the most pressing open questions.

This was the starting point to initiate the SimGrow workshop.

Read the full workshop report here.

Continue reading Simulation of chemistry‐driven growth phenomena for metastable materials – SimGrow 2015

Scientific Highlight – December 2015

Exotic s-wave superconductivity in alkali-doped fullerides
Yusuke Nomura, Shiro Sakai, Massimo Capone and Ryotaro Arita
Alkali-doped fullerides (A3C60 with A= K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the mechanism of the high-Tc superconductivity.
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This article reviews recent ab initio calculations, which have succeeded in reproducing comprehensively the experimental phase diagram with high accuracy and elucidated an unusual cooperation between the electron-phonon coupling and the electron-electron interactions leading to Mott localization to realize an unconventional s-wave superconductivity in the alkali-doped fullerides.

October 2015 Highlight – 2015 Psi-k Conference

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We dedicate this issue of the Psi-k Newsletter to the 2015 Psi-k Conference.  We provide a brief overview of the conference, some photos of the event, a breakdown of the origins of the conference attendees, and a series of short personal reflections by a few researchers who very kindly took the time to provide their impressions.  We also provide a copy of the full scientific program at the end, and include a section about the Volker Heine Young Investigator Award and its associated symposium.

Psi-kConf1Read the full highlight here.

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