🤖 AI Summary
This work addresses the inability of existing machine learning Hamiltonian models to accurately capture macroscopic electrostatic behavior in polar crystals and heterostructures due to their neglect of long-range Coulomb interactions. The authors propose HamGNN-LR, a novel model that, for the first time, rigorously derives long-range Hamiltonian matrix elements within a non-orthogonal atomic orbital basis by variationally decomposing the electrostatic energy and establishing a consistent mapping from the density matrix to effective atomic charges. By integrating E(3)-equivariant message passing with reciprocal-space Ewald summation, the model constructs a dual-channel architecture that fuses real- and reciprocal-space information under physical constraints. Evaluated on ZnO, CdSe/ZnS, and GaN/AlN systems, HamGNN-LR reduces prediction errors by 2–3×, effectively eliminates staircasing artifacts under built-in electric fields, and demonstrates excellent cross-scale transferability.
📝 Abstract
Machine-learning electronic Hamiltonians achieve orders-of-magnitude speedups over density-functional theory, yet current models omit long-range Coulomb interactions that govern physics in polar crystals and heterostructures. We derive closed-form long-range Hamiltonian matrix elements in a nonorthogonal atomic-orbital basis through variational decomposition of the electrostatic energy, deriving a variationally consistent mapping from the electron density matrix to effective atomic charges. We implement this framework in HamGNN-LR, a dual-channel architecture combining E(3)-equivariant message passing with reciprocal-space Ewald summation. Benchmarks demonstrate that physics-based long-range corrections are essential: purely data-driven attention mechanisms fail to capture macroscopic electrostatic potentials. Benchmarks on polar ZnO slabs, CdSe/ZnS heterostructures, and GaN/AlN superlattices show two- to threefold error reductions and robust transferability to systems far beyond training sizes, eliminating the characteristic staircase artifacts that plague short-range models in the presence of built-in electric fields.