Publications

Presentation on dispersion interactions in exciton-localized states given at the OpenMolcas developers' workshop, June 2022. ...Read more

Presentation on "Optimization of Jastrow factors for Similarity Transformed quantum chemical methods" for the OpenMolcas developers' workshop 2022. ...Read more

Within the "Targeting REal chemical accuracy at the eXascale" (TREX) European center of excellence, we are building a file format and library to help inter-operability between quantum chemistry codes, and also to help the reproducibility of calculations. This is a tedious task because the codes have different conventions such as the normalization of the basis, the ordering of atomic orbitals, the phase factors in the CI coefficients, etc... ...Read more

Range-separated DFT was implemented within selected configuration interaction (sCI).[1] The PBE density functional is used for the short-range correlation, and CIPSI is used for the long-range. The introduction of DFT for short range correlation has multiple benefits for QMC simulations. First, it reduces significantly the size of the CI expansion by several orders of magnitude. Secondly, it mimics the effect of a short-range correlation factor such as the Jastrow factor used in QMC simulations, leading to a significant improvement of the nodal surfaces, and energy differences. ...Read more

Quantum Monte Carlo (QMC) methods belong to one of the most accurate families of numerical approaches for materials and electronic structure calculations. Moreover, the steady increase of computer power in HPC machines is very much suitable for the development and usage of stochastic ab initio methods, which - beside the high precision - are highly parallelizable and enjoy a favorable scaling with the system size. ...Read more

Thee QMC Hands-on Summer Workshop was held from 20 to 23 July 2022.  The video recording of the event is avaialable here.  Hands-on tutorials are available on the following links: ...Read more

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 software solutions for quantum mechanical simulations at the exascale. The final goal of the project is to develop a set of flagship Quantum Monte Carlo codes, able to exploit the capabilities of the recent exascale computers at their highest. ...Read more

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