Research Digest — 2026-03-23¶
Papers¶
1. An Analytical Model of Alkali Metal Dendrite Growth in Ceramic Solid Electrolytes based on Griffith's Theory¶
Source: arXiv (cond-mat.mtrl-sci), Mar 20, 2026 · 📅 2026-03-20 · ↗ Open paper
Dendrite propagation in ceramic SEs is controlled by a competition between mechanical fracture energy (Griffith's theory) and Joule heating from current detouring around the dendrite. The critical current density follows \(J_{\mathrm{crit}} \propto c_{\max}^{3/2}\), where \(c_{\max}\) is the longest pre-existing interfacial defect length. Analytical fracture mechanics coupled with electrostatic energy balance. Derives a closed-form scaling law for critical current density in ceramic SEs based on minimal power dissipation, and predicts that \(J_{\mathrm{crit}}\) scattering must follow a Weibull distribution — analogous to tensile strength statistics in brittle ceramics.
Relevance to DENG.Group
Directly relevant to Shoutong Jin's phase field dendrite work. Provides an analytical framework for understanding critical current density in ceramic solid electrolytes, complementing the group's computational phase field approach with a mechanics-based analytical model. Shoutong Jin can incorporate the \(J_{\mathrm{crit}} \propto c_{\max}^{3/2}\) scaling into phase field simulations to set physically motivated boundary conditions. The Weibull distribution prediction offers a testable hypothesis: measure \(J_{\mathrm{crit}}\) across many samples with controlled defect populations and check for Weibull scaling.
2. Prediction and Experimental Verification of Electrolyte Solvation Structure from an OMol25-Trained Interatomic Potential¶
Source: arXiv (physics.chem-ph), Mar 20, 2026 · 📅 2026-03-20 · ↗ Open paper
The OMol25-trained Universal Model of Atoms (UMA-OMol) predicts experimental densities and X-ray structure factors in Na-ion electrolytes with substantially better agreement than materials-only models, revealing systematic trends in solvation structure as a function of cation/anion identity, concentration, and solvent topology. MLIP-driven molecular dynamics with experimental validation (X-ray structure factors, density measurements). Comparison of OMol25-trained vs materials-trained MLIPs across diverse Na-ion electrolyte compositions. First systematic, experimentally validated comparison of molecular vs materials training data for battery electrolyte MLIPs. Shows that OMol25 captures ion-solvent interactions and contact ion pair formation that materials-trained models completely miss.
Relevance to DENG.Group
Demonstrates that MLIPs trained on molecular datasets (OMol25) dramatically outperform materials-trained MLIPs for liquid electrolyte structure prediction. This has implications for Yanhao Deng's MLIP work — the choice of training dataset matters as much as architecture. Yanhao should test whether halide electrolyte MLIPs benefit from fine-tuning with molecular DFT data alongside bulk crystal data. The solvation structure analysis pipeline (CIPs, ion correlations) is directly transferable to investigating \(\ce{Li+}\) environments in polymer electrolytes (Naibing Wu).
3. Multi-fidelity Machine Learning Interatomic Potentials for Charged Point Defects¶
Source: arXiv (cond-mat.mtrl-sci), Mar 5, 2026 · 📅 2026-03-05 · ↗ Open paper
Foundation MLIPs fail at describing charged point defects because defect environments involve coordination and electron counts far from training data. A global defect charge embedding combined with multi-fidelity training (semi-local + hybrid functional data) yields defect-capable force fields that predict charge-transition levels in quantitative agreement with direct DFT. Global defect charge embeddings in MLIP architecture. Multi-fidelity training combining PBE-level data (abundant, cheap) with hybrid functional data (scarce, accurate) for charged defects in \(\ce{Sb2Se3}\). First explicit demonstration that foundation MLIPs fail for charged defect physics, with a concrete solution: charge-state-dependent global embeddings plus multi-fidelity training. The resulting model predicts charge-transition levels at a fraction of DFT cost.
Relevance to DENG.Group
Directly addresses a major gap in Jerry's group: current MLIPs fail for charged defects — exactly what Yan Li and Mengke Li study in halide electrolytes. This paper introduces global defect charge embeddings and a multi-fidelity approach that could transform defect MLIP accuracy. This is a must-try for halide electrolyte defect work. Yan Li and Mengke Li should apply the multi-fidelity approach to \(\ce{Li3YCl6}\) charged vacancies and antisite defects. The defect charge embedding concept is architecture-agnostic and could be combined with MACE or CHGNet.
4. Proof-Carrying Materials: Falsifiable Safety Certificates for Machine-Learned Interatomic Potentials¶
Source: arXiv (cond-mat.mtrl-sci), Mar 12, 2026 · 📅 2026-03-12 · ↗ Open paper
Proof-Carrying Materials (PCM) provides falsifiable safety certificates for MLIP predictions through adversarial falsification, bootstrap envelope refinement with 95% confidence intervals, and formal Lean 4 certification. Auditing CHGNet, TensorNet, and MACE reveals architecture-specific blind spots with near-zero pairwise error correlations. Three-stage framework: adversarial falsification across compositional space, bootstrap envelope refinement, and Lean 4 formal verification. Validated on 25,000-material benchmark and independent Quantum ESPRESSO calculations. First formal reliability guarantee framework for MLIP-based materials screening. Shows that MACE, CHGNet, and TensorNet have completely different blind spots (r ≤ 0.13 error correlation), meaning ensembles are essential — a single model is never sufficient.
Relevance to DENG.Group
A single MLIP used as a stability filter misses 93% of DFT-stable materials (recall 0.07). This is a wake-up call for the group's high-throughput screening workflows — any results obtained from single-MLIP screening need formal reliability guarantees. Jerry should adopt PCM-style adversarial validation for any halide electrolyte screening campaigns. The risk model (AUC-ROC = 0.938) that predicts failures on unseen materials and transfers across architectures is directly usable as a pre-screening reliability filter.
5. Scaling Machine Learning Interatomic Potentials with Mixtures of Experts¶
Source: arXiv (physics.chem-ph), Mar 9, 2026 · 📅 2026-03-09 · ↗ Open paper
Sparse MoE with element-wise routing and shared experts yields substantial performance gains over monolithic models. Nonlinear MoE outperforms linear MoE, and the routing patterns reveal chemically interpretable expert specialization — different elements are handled by different expert subnetworks. Systematic development of MoE and MoLE architectures for MLIPs with different routing strategies (element-wise, configuration-level, global). Benchmarked across three major MLIP datasets. First systematic study of MoE for MLIPs showing that element-wise routing with sparse activation consistently outperforms other strategies. The chemically interpretable routing patterns are novel — the model effectively learns a periodic-table-aware decomposition of chemical space.
Relevance to DENG.Group
From Weinan E's group (pioneer of DeePMD). Introduces Mixture-of-Experts (MoE) for MLIPs — a scalable architecture that achieves state-of-the-art accuracy on OMol25, OMat24, and OC20M by learning element-specific expert specialization aligned with periodic-table trends. Yanhao Deng should benchmark MoE-MLIP against MACE for halide electrolyte systems. If MoE handles halide elements more effectively through specialized experts, it could improve accuracy for \(\ce{Li3YCl6}\) and related compositions without increasing inference cost.
6. A Recipe for Scalable Attention-Based MLIPs: Unlocking Long-Range Accuracy with All-to-All Node Attention¶
Source: arXiv (cs.LG), Mar 6, 2026 · 📅 2026-03-06 · ↗ Open paper
AllScAIP uses an all-to-all node attention component to capture long-range interactions in a fully data-driven manner. As data and model size scale, physics-based inductive biases become less important — or even counterproductive — while all-to-all attention remains critical for accuracy on electrolyte-scale systems. Attention-based, energy-conserving MLIP architecture trained on O(100 million) samples. Benchmarked on OMol25, OMat24, and OC20M. Includes stable long-timescale MD validation against experimental observables. Shows that physics-based inductive biases (equivariance, message passing locality) improve sample efficiency in small-data regimes but reverse at scale, while all-to-all attention consistently matters. This challenges the prevailing assumption that equivariant architectures are always superior.
Relevance to DENG.Group
Complements the long-range MLIP theme from the March 21 digest (EquiEwald, self-consistent electrostatic MLIPs). AllScAIP takes a data-driven approach to long-range interactions via all-to-all attention, rather than explicit physics-based corrections. The scaling findings are relevant for Jerry's group when deciding how much DFT training data to generate for halide electrolyte MLIPs. If the group can produce >10M training samples, all-to-all attention may outperform equivariant MACE.