Jorge A. Charry Martinez - Research interests

Quantum Monte Carlo

Quantum Monte Carlo (QMC) methods, are a family of highly parallelizable computational techniques used to provide an accurate solution to the quantum many-body problem, that can fully exploit the advantages of modern high-performance computing facilities. To this end, we proposed and applied a new efficient wave function ansatz for electron-positron systems based on QMC methods. These new developments are implemented in the QMeCha computational software, a QMC code developed in by Dr. Matteo Barborini. With this new methodology, we examine the physical and chemical properties of many benchmark positronic complexes.

For further information, see J. Charry, M. Barborini, A. Tkatchenko. "Correlated Wave Functions for Electron–Positron Interactions in Atoms and Molecules" J. Chem. Theory Comput. 18, 4, 2267–2280, 2022. [Link]

Researchers: Matteo Barborini, Matej Ditte, Alexandre Tkatchenko

Polarizability and electric response properties

We are exploring how to unveil the electron-positron wave function structure and the positron binding mechanisms through the evaluation of their response properties to an external electric field, computed by QMC techniques. In particular, we focus on analyzing dipole polarizabilities of positronic compounds, as well as regular electronic structure systems.

Researchers: Matteo Barborini, Alexandre Tkatchenko

Any Particle Molecular Orbital (APMO) Method

In this approach, any type of particles can be treated at the same level of theory of electrons. At the APMO/HF level, the total wavefunction is approximated as a product of a single-configurational wavefunction for each quantum species (electrons, nuclei, positrons, muons).

Review paper on A. Reyes, F. Moncada J. Charry. "The Any Particle Molecular Orbital approach: a short review of the theory and applications". Int. J. Quantum Chem. 119, e25705, 2019. [Link]

Researchers: Andrés Reyes' group.

LOWDIN Code

LOWDIN is a computational chemistry software developed to perform calculations for any quantum particle under the APMO approach. Lowdin is able to perform APMO calculations at RHF, UHF, MP2, EP2 and DFT levels of theory.

For further information visit https://github.com/efposadac/openLOWDIN

Researchers: Andres Reyes' group and Roberto Flores-Moreno's group.

Positrons in molecular systems

We are studying the interactions between molecular systems and one positron employing the LOWDIN code and QMeCha code.

Researchers: Andrés Reyes' group, Matteo Barborini, Alexandre Tkatchenko, Marcio Varella.

A symbolic computing software for multicomponent second quantization equations.

Symbolic algebra applied to quantum chemistry has been a powerful tool for the manipulation of second-quantized operators, which is an essential procedure required in the formulation of many-body quantum-mechanical methods. Here we present the development of a python code to perform the formulation of the propagator equations for different types of quantum species, by handling the second-quantized expressions with Wick's theorem, other second quantization properties, and basic algebra.

[Code]

Researchers: Jonathan Romero, Andrés Reyes, Roberto Flores-Moreno.