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Cristobál Méndez

Publications and source records attributed to Cristobál Méndez.

2 recordsLinked to original sources
arXiv2026

Effective Atom Theory: Gradient-Driven Materials Design

We introduce Effective Atom Theory (EAT), which embeds discrete atomic identities into a continuous differentiable space. During optimization, sites pass through temporary effective mixtures, then are driven to fully discrete, physically realizable atoms. This enables gradient-based optimization in DFT and MLIPs, yielding orders-of-magnitude acceleration over discrete methods. EAT recovers the exact ground state of NaCl in a 128 atom cell, reconstructs the Cu-Pd phase diagram, optimizes high-entropy oxides for oxygen evolution, and discovers bonding topologies as demonstrated for SrTiO3.

cond-mat.mtrl-sci↗
arXiv2026

Hereditary Effective Atom Theory for Large-Scale Atomic Structure Prediction

Predicting the atomic structure of large systems requires simultaneous exploration of atomic positions, species, and, generally, the number of atoms. The combinatorial growth of possible arrangements can make this search difficult even for standard genetic algorithms. We introduce Hereditary Effective Atom Theory (HEAT), which integrates Effective Atom Theory into a genetic algorithm to enable efficient global search through a differentiable effective-atom representation. Central to the method is a crossover scheme that directly superimposes two parent structures and relaxes the combined structure. HEAT outperforms conventional genetic-algorithm baselines in recovering a missing 240-atom H sublattice, predicting a 364-atom edge-dislocation core, and reconstructing twisted-bilayer $\mathrm{WSe_2}$ containing 1150 atoms from ptychographic constraints. These results demonstrate how continuous effective-atom relaxation improves the exploration of large combinatorial structure spaces.

cond-mat.mtrl-sci↗