Publications

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 sort most of the planned activities: a distinction is made based on the subject (HPC, quantum chemistry), between the planned, upcoming and future events, between events internal to the consortium and events open to external audiences. Document D6.2 is structured into 6 Chapters. ...Read more

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-throughput computing (HTC) have enabled us to simulate large-scale complex processes and analyze tremendous amounts of data, benefitting applications ranging from climate research and drug discovery to material design. Emerging exascale computers will make the best even better, 50 times faster than today's most powerful supercomputers. ...Read more

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 architectures. This ranges from the efficient use of SIMD instructions to the use of highly parallel compute accelerators like Graphics Processing Units (GPUs). ...Read more

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 will be given by walking through a detailed DGEMM example (Section 3). Finally, some preliminary performance results on a key QMCkl routine (JASTROW computation will be given). ...Read more

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), we investigate ways to overcome new difficulties that will arise when running exascale simulations. ...Read more

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 materials science. Importantly, due to their inherent parallelizability and high computational cost, QMC approaches, and thus TREX is uniquely positioned to fully exploit the massive parallelism of the upcoming exascale supercomputer architectures. ...Read more

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 codes independently for exascale architectures, or re-writing a new monolithic code, our strategy is instead to design a new library, Quantum Monte Carlo kernel library (QMCkl), containing the state-of-the-art expertise in the implementation of specific kernels present in each of the three codes. ...Read more

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

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.  ...Read more

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 ingredient to successfully accomplish the above target is ensuring that the libraries do provide an improvement in terms of performance, and not at the expense of accuracy. Also, since development is an ongoing process, it is vital to be able to detect early on if a new update caused regressions, in terms of accuracy, performance or stability. ...Read more