Want to learn more about TREX? On this page, you can find our archive of informative publication materials: reports, deliverables, presentations and articles from experts within the TREX community speaking about various TREX related topics. All the public materials published by TREX partners are available on the TREX Zenodo Community: Zenodo

Heat flux for semilocal machine-learning potentials

Physical Review B 108, L100302

Marcel F. Langer, Florian Knoop, Christian Carbogno, Matthias Scheffler, Matthias Rupp


Ultra-fast interpretable machine-learning potentials

npj Computational Materials

Stephen R. Xie, Matthias Rupp, Richard G. Hennig


TREXIO: A file format and library for quantum chemistry

Journal of Chemical Physics

Evgeny Posenitskiy, Vijay Gopal Chilkuri, Abdallah Ammar , Michał Hapka, Katarzyna Pernal, Ravindra Shinde, Edgar Josué Landinez Borda, Claudia Filippi , Kosuke Nakano, Otto Kohulák, Sandro Sorella, Pablo de Oliveira Castro, William Jalby, Pablo López Ríos , Ali Alavi , Anthony Scemama


Quantum phase diagram of high-pressure hydrogen

Nature Physics

Lorenzo Monacelli, Michele Casula, Kosuke Nakano, Sandro Sorella, Francesco Mauri


TREX Workshop: Code Tuning for the Exascale

Jalby, William; Valensi, Cédric; Blaas-Schenner, Claudia; Vialov, Ivan; Vysocký, Ondřej; Tomáš PANOC; Vavrik, Radim

The TREX project, in collaboration with the Austrian, Czech, and Slovak National Competence Centres for HPC, is hosting the "Code Tuning for the Exascale" workshop in Brat.. Read more

45 Views114 Downloads

TREX Hackathon III at CINECA

Bettencourt, Matt; Rossi, Giacomo; Molinari, Diego; Ippolito, Mariella

The TREX Centre of Excellence, together with CINECA, has organised the TREX Hackathon III in Bologna, Italy. The Hackathon was held in CINECA's Dipartimento HP.. Read more

33 Views34 Downloads

TREX High Performance Software Solutions for Quantum Mechanical Simulations at the Exascale

Filippi, Claudia; Alavi, Ali; Pernal, Kasia; Nakano, Kosuke; Posenitskiy, Evgeny; Scemama, Anthony; Pittonet, Sara; Shinde, Ravindra; López Ríos, Pablo; Tenti, Giacomo; Zen, Andrea; Shepard, Stuart

Here is the presentation from the TREX Webinar on "High Performance Software Solutions for Quantum Mechanical Simulations at the Exascale” that took place on 8 February 2023.

This webinar walked participants through TREX&.. Read more

20 Views26 Downloads

TREX : an innovative view of HPC usage applied to Quantum Monte Carlo simulations

Scemama, Anthony; de Oliveira Castro, Pablo; Valensi, Cedric; Jalby, William

    TREX : an innovative view of HPC usage applied to Quantum Monte Carlo simulations                                               .. Read more

77 Views94 Downloads

Library development within TREX

Anthony Scemama

Presentation of:


- QMCkl


Read more

74 Views87 Downloads

Guidelines for improving the performance of computer programs

Anthony Scemama

Webinar organized by Institut Chimie Radicalaire & Centre de Calcul Intensif Aix-Marseille.

The technological evolution of computer hardware is such that gaining performance in computer codes has become increasingly difficult over the last .. Read more

93 Views112 Downloads

Software development strategy in the TREX Center of Excellence

Scemama, Anthony; Filippi, Claudia

Video available here:

Targeting Real chemical accuracy at the EXascale

Quantum mechanical simulations play an important role in .. Read more

72 Views78 Downloads

Density Matrix Renormalization Group for Transcorrelated Hamiltonians: Ground and Excited States in ab initio Systems

Journal of Chemical Physics

Ke Liao, Huanchen Zhai, Evelin Martine Christlmaier, Pablo López Ríos, Daniel Kats, Thomas Schraivogel, Ali Alavi


Double Excitation Energies from Quantum Monte Carlo Using State-Specific Energy Optimization

Journal of Chemical Theory and Computation 2022, 18, 11, 6722–6731

Stuart Shepard, Ramón L. Panadés-Barrueta, Saverio Moroni, Anthony Scemama, Claudia Filippi


High-pressure II-III phase transition in solid hydrogen: Insights from state-of-the-art ab initio calculations

Physical Review Research 4, L042009

Maria Hellgren, Damian Contant, Thomas Pitts, Michele Casula


Extension of selected configuration interaction for transcorrelated methods

Journal of Chemical Physics 57, 134107 (2022)

Abdallah Ammar, Anthony Scemama, Emmanuel Giner


TREX QMC Hands-on Summer Workshop: Post Event Report

The QMC Hands-on Summer Workshop saw 21 PhD and Masters students from Europe and beyond get a unique insight into the world of QMC and meet some of the world’s leading experts in the field.

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Optimization of large determinant expansions in quantum Monte Carlo

Journal of Chemical Theory and Computation, 2022, 18, 9, 5325–5336

Abdallah Ammar, Emmanuel Giner, Anthony Scemama


Hydrogen phase-IV characterization by full account of quantum anharmonicity

Physical Review B 106, 054109

Tommaso Morresi, Rodolphe Vuilleumier, Michele Casula


Dispersion Interactions between Molecules in and out of Equilibrium Geometry: Visualization and Analysis

The Journal of Physical Chemistry A 2022, 126, 7, 1312–1319

Piotr H. Kowalski, Agnieszka Krzemińska, Katarzyna Pernal, Ewa Pastorczak


Quantum phase diagram of high-pressure hydrogen

Lorenzo Monacelli, Michele Casula, Kosuke Nakano, Sandro Sorella, Francesco Mauri


Leveraging stochastic electronic structure methods at the exascale

Coppens, François; Jalby, William; Scemama, Anthony

TREX is taking part in the EuroHPC Summit 2023 in Göteborg, Sweden, during the poster session on day 1 (20 March).

We present here the software development strategy and the current achievements of the European Centre of Excellence “T.. Read more

16 Views16 Downloads

Libraries developed in the TREX Center of Excellence - poster presented at the CECAM Workshop 2022

Anthony Scemama; William Jalby; Vijay Gopal Chilkuri; Evgeny Posenitskiy; Pablo de Oliveira Castro; Cedric Valensi

The TREX European Center of Excellence focuses on high-accuracy quantum mechanical methods, essential in many different fields of application such as new material design or photochemistry. Among these methods, Quantum Monte Carlo (QMC) approaches are partic.. Read more

33 Views24 Downloads

Championing stochastic electronic structure methods with CHAMP

Ravindra Shinde; Edgar Landinez; Stuart Shepard; Alice Cuzzocrea; Anthony Scemama; Claudia Filippi

The poster was presented at the Psi-k 2022 conference, August 22-25.

We present the recent progress in developing a high-performance and user-friendly program suite – the Cornell-Holland Ab-initio Materials Package (CHAMP) -- for performing ac.. Read more

40 Views27 Downloads

TurboGenius: A python suite for implementing workflows with ab initio quantum Monte Carlo code "TurboRVB"

Kosuke Nakano

The poster was presented at the Psi-k 2022 conference, August 22-25.

Kosuke Nakano, Scuola Internazionale Superiore di Studi Avanzati (SISSA), Japan Advanced Institute of Science and Technology (JAIST)

Ab initio quantum Monte Carlo study inv.. Read more

65 Views47 Downloads

TREX at TERATEC 2022: Enabling the community codes for stochastic quantum chemical simulations at he exascale

Axel Auweter; Michele Casula; William Jalby; Sara Pittonet; Jean-Marc Denis; Romain Dolbeau; Marie-Ann Garigue; Craig Prunty

The poster was presented at Teratec 2022, June 14-15.

Computers can perform extremely fast calculations which would take human beings years to accomplish, accelerating innovation to unprecedented levels. High-performance computing (HPC) and high-thr.. Read more

31 Views22 Downloads

TREX Targeting REal Accuracy at eXascale

Affinito, Fabio

In order to compete in the demanding rush in high-precision quantum chemical simulation methods, the TREX Center of Excellence (CoE) federates European scientists, High Performance Computing (HPC) stakeholders, and SMEs to develop and apply high-performance.. Read more

75 Views56 Downloads
Project deliverable

D6.2 – First report on the status of organisation of training events and activities, including validation surveys. V1.0

Stich, Ivan

The current document D6.2 describes and details the structure of the training and education strategy and the plans of the events that have taken place at the time of writing and those planned for the remaining project lifetime. Various criteria are used to .. Read more

10 Views12 Downloads
Project deliverable

D3.3 – Initial report on the performance characteristics on relevant hardware for upcoming supercomputers

Pleiter, Dirk

This deliverable documents the initial performance analysis results obtained for all 6 TREX flagship applications. The focus was, in particular, the scaling of the application and the ability to exploit parallelism at all the different levels of modern HPC .. Read more

11 Views10 Downloads
Project deliverable

D4.2 – Report on algorithms for exascale robustness (fault tolerance and large-scale communications) in QMC flagship codes

Alavi, Ali

We expect exascale machines to enable QMC applications on larger systems than those that can be treated today. This implies that systems will have larger numbers of electrons, and/or larger Configuration Interaction (CI) expansions. In this Work Package (WP.. Read more

13 Views17 Downloads
Project deliverable

D3.2 – Initial public release of high-performance software components

Jalby, William

In this first document, after a brief Introduction (Section 1), we are describing the rationale for QMCkl design guidelines (Section 2). In particular, objectives and general methodology will be highlighted. Then, more precise details on the methodology wil.. Read more

10 Views11 Downloads
Project deliverable

D2.4 – Report on pre-release of an integrated platform with inter-operable Open Source flagship codes, including the I/O and, gradually, the QMCkl libraries

Sorella, Sandro

The TREX project is in the field of high-accuracy quantum chemical and materials simulations with a special focus on Quantum Monte Carlo (QMC) approaches to the solution of the quantum many-body problem at the heart of atomistic physics, chemistry, and mate.. Read more

8 Views9 Downloads
Project deliverable

D1.2 - Report on pre-release of open-source human-readable implementation of QMCkl

Scemama, Anthony

There are three different Quantum Monte Carlo (QMC) codes in the Targeting REal chemical accuracy at the eXascale (TREX) Center of Excellence (CoE), TurboRVB, Champ, and QMC=Chem, each with its own strengths and weaknesses. Instead of optimizing the three c.. Read more

28 Views27 Downloads
Project deliverable

D2.2 – Report on the final release of the I/O library.

Scemama, Anthony

A report for the progress of this Work Package (WP) was made in month 6: D2.1 - Report on the first alpha release of the I/O library, ready for WP4. We recall in this section the key points of the developed library. 

The objectiv.. Read more

16 Views15 Downloads
Project deliverable

D2.3 – Benchmark data for domain-specific and non-regression performance tests

Valensi, Cédric

One of the main goals of the TREX project is the implementation of optimised libraries for QMC computation (QMCkl) and I/O for interoperability and synergic applications of TREX codes as well as for use by other software packages outside TREX. A key ingredi.. Read more

15 Views15 Downloads
Project deliverable

D7.3 – Communication, dissemination, and stakeholders engagement strategy and plan V1.0

Abergas-Arteza, Julie

The main goal of the TREX Centre of Excellence (CoE) is to enable the community codes for stochastic quantum chemical simulations to successfully exploit the most advanced European computing facilities, i.e., the EuroHPC pre-exascale and exascale machines, .. Read more

21 Views22 Downloads
Project deliverable

D8.1 - Project handbook

Filippi, Claudia; Beerens, Jan

This Project Handbook describes how the management procedures and processes are defined and implemented within the TREX project. This includes the CoE governance structure and associated infrastructure, as well as the project operational guidelines. Managem.. Read more

14 Views18 Downloads
Project deliverable

D2.1 – Report on a first alpha release of the I/O library, ready for WP4

Sorella, Sandro; Scemama, Anthony

We build a library to help inter-operability between codes in the field of quantum chemistry, primarily focused on enabling the communication of data between the flagship codes of the Targeting REal chemical accuracy at the eXascale (TREX) Center of Excelle.. Read more

26 Views21 Downloads
Project deliverable

D6.1 – Training and Education Strategy and Plan V1.0

Dubecky, Matus

The current document D6.1 describes the structure and details of the training and education strategy and the plans for the events that will take place during the TREX project lifetime. The details included are the best available at the time of writing (regu.. Read more

11 Views18 Downloads
Project deliverable

D7.2 – TREX Web platform

Schillaci, Andrea

The website will also act as the main hub to connect with relevant TREX stakeholders and raise awareness around High Performance Computing (HPC), High-accuracy Quantum Chemistry and Materials Science, and Exascale Computing.

This document .. Read more

10 Views10 Downloads
Project deliverable

D7.1 – TREX Branding and communication kit

Schillaci, Andrea

This document is therefore intended to report about the TREX Branding and Communication Kit, one of the first online tools developed to pursue an optimal development of the TREX brand and visual identity and to start spreading project recognition among rele.. Read more

10 Views12 Downloads

Reference Excitation Energies of Increasingly Large Molecules: A QMC Study of Cyanine Dyes

Journal of Chemical Theory and Computation 2022, 18, 2, 1089–1095

Alice Cuzzocrea, Saverio Moroni, Anthony Scemama, Claudia Filippi


Quantum Rényi entropy by optimal thermodynamic integration paths

Physical Review Research 4, L032002

Miha Srdinšek, Michele Casula, Rodolphe Vuilleumier


Energy Derivatives in Real-Space Diffusion Monte Carlo

Journal of Chemical Theory and Computation 2022, 18, 1, 118–123

Jesse van Rhijn, Claudia Filippi, Stefania De Palo, Saverio Moroni


A new generation of HPC developers using quantum Monte Carlo (QMC) methods is growing

Outcomes of the first TREX e-School on Quantum Monte Carlo with TurboRVB

Quantum Monte Carlo (QMC) methods have never been so appealing according to the engagement rate of the first edition of the TREX e-School on Quantum Monte Carlo. Jointly organised by TREX, the Centre of Excellence in

Read more

Ground-state properties of the narrowest zigzag graphene nanoribbon from quantum Monte Carlo and comparison with density functional theory

Journal of Chemical Physics 156, 084112 (2022)

Raghavendra Meena, Guanna Li, Michele Casula


Ultra-fast interpretable machine-learning potentials

Chemical Physics (2021)

Stephen R. Xie, Matthias Rupp, Richard G. Hennig


TREX featured at the ETP4HPC Handbook 2021

  The 2021 edition of the ETP4HPC Handbook of HPC projects is available.

This 2021 issue is bigger than ever, listing 68 ongoing projects (and 34 more finalised projects are referenced). This Handbook aims to provide a comprehensive overview of all projects in the HPC arena and will help you

Read more

Spin-Pure Stochastic-CASSCF via GUGA-FCIQMC Applied to Iron–Sulfur Clusters

Journal of Chemical Theory and Computation 17, 5684–5703 (2021)

Werner Dobrautz, Oskar Weser, Nikolay A. Bogdanov, Ali Alavi, Giovanni Li Manni


Range-separated multiconfigurational density functional theory methods

WIREs Compututational Molecular Science (2021)

Katarzyna Pernal, Michał Hapka


Density Functional Geometries and Zero-Point Energies in Ab Initio Thermochemical Treatments of Compounds with First-Row Atoms (H, C, N, O, F)

Journal of Chemical Theory and Computation 2021, 17, 8, 4872–4890

Dirk Bakowies, O. Anatole von Lilienfeld


Probing anharmonic phonons by quantum correlators: A path integral approach

Journal of Chemical Physics 154, 224108 (2021)

Tommaso Morresi, Lorenzo Paulatto, Rodolphe Vuilleumier, Michele Casula


Tailoring CIPSI Expansions for QMC Calculations of Electronic Excitations: The Case Study of Thiophene

Journal of Chemical Theory and Computation 17, 3426–3434 (2021)

Monika Dash, Saverio Moroni, Claudia Filippi, Anthony Scemama


Localization versus inhomogeneous superfluidity: Submonolayer 4He on fluorographene, hexagonal boron nitride, and graphene

PHYSICAL REVIEW B 103, 174514 (2021)

Saverio Moroni, Francesco Ancilotto, Pier Luigi Silvestrelli, Luciano Reatto


Spin-adapted selected configuration interaction in a determinant basis

Advances in Quantum Chemistry

Vijay Gopal Chilkuri, Thomas Applencourt, Kevin Gasperich, Pierre-François Loos, Anthony Scemama


Machine learning based energy-free structure predictions of molecules (closed and open-shell), transition states, and solids

Nature Communications 12, 4468 (2021)

Dominik Lemm, Guido Falk von Rudorff, O. Anatole von Lilienfeld


Elucidating atmospheric brown carbon -- Supplanting chemical intuition with exhaustive enumeration and machine learning

Environmental Science & Technology 55, 8447–8457 (2021)

Enrico Tapavicza, Guido Falk von Rudorff, David O. De Haan, Mario Contin, Christian George, Matthieu Riva, O. Anatole von Lilienfeld


Machine Learning of Free Energies in Chemical Compound Space Using Ensemble Representations: Reaching Experimental Uncertainty for Solvation

Journal Of Chemical Physics 154, 134113 (2021)

Jan Weinreich, Nicholas J. Browning, O. Anatole von Lilienfeld


Ab initio machine learning in chemical compound space

Chemical Reviews 2021, 121, 16, 10001–10036

Bing Huang, O. Anatole von Lilienfeld