Electron-affinity difference distributions as an organizing principle for superconductivity, enabling the discovery of PtPb₃Bi

摘要

预测超导转变温度（T_c）仍面临挑战。本研究提出可解释且结构、化学感知的高斯过程模型 GP-T_c，通过图元直方图编码局部键合环境，并结合地球移动距离构建有效核，实现带不确定度的 T_c 预测。分析表明，仅需相邻原子间电子亲和势差分布、原子间距及少量元素特征即可预测不同超导家族的 T_c，揭示电子亲和势差是连接局域键合与宏观超导性的关键化学参数，且机制无关。该模型复现了无限层镍酸盐 Nd₀.8Sr₀.2NiO₂ 的实验 T_c 范围，并预测化学计量 PtPb₃Bi 的超导性，实验证实 T_c≈3 K。此外，GP-T_c 通过网页接口开放，并识别出 SrNiO₂ 与 K(PRh)₂ 等高优先级候选材料。

材料

• PtPb₃Bi
• Nd₀.8Sr₀.2NiO₂
• SrNiO₂
• K(PRh)₂

方法

• Gaussian process regression
• graphlet histogram featurization
• Earth Mover's Distance kernel
• superconductivity classification
• high-throughput ICSD screening
• magnetic susceptibility measurement
• electronic transport measurement
• Werthamer-Helfand-Hohenberg analysis

关键词

• electron affinity difference
• superconducting transition temperature
• structure aware machine learning
• uncertainty quantification
• interpretable machine learning
• local bonding environment
• high throughput superconductivity screening
• mechanism agnostic prediction

亮点

• PtPb₃Bi is a previously unknown stoichiometric superconductor discovered through prospective experimental validation of GP-T_c, with a unique structure type hosting face-sharing dimerized [Pt₂Pb₈Bi₄] bicapped trigonal prismatic units.
• Electron-affinity difference, though overlooked in favor of Pauling electronegativity, emerges as the most informative descriptor and maps onto charge-transfer energy in the Zaanen-Sawatzky-Allen framework for transition-metal oxides.
• GP-T_c is made openly accessible through a web interface for crystal-structure-based prediction from standard CIF files.
• SrNiO₂ is predicted to have T_c of about 51.5 K, substantially higher than any known nickelate superconductor, providing a concrete experimental target.

结论

• The distribution of electron-affinity differences between neighboring atoms, together with interatomic distances and simple elemental features, suffices to predict superconducting transition temperature across disparate superconducting families.
• GP-T_c reproduces the experimentally reported T_c range of the infinite-layer nickelate Nd₀.8Sr₀.2NiO₂ and predicts and experimentally confirms superconductivity in stoichiometric PtPb₃Bi with T_c approximately 3 K.
• The framework identifies additional high-priority superconducting candidates, including SrNiO₂ with predicted T_c of 51.5 K and K(PRh)₂.
• Electron-affinity difference provides a mechanism-agnostic physical basis that captures T_c across conventional and unconventional families, including doped charge transfer insulators.
• The predictive feature space collapses from 67 descriptors to just four second-order graphlet features, dominated by electron-affinity difference and interatomic distance.

主要论断

本批次暂无数据。

研究流程

本批次暂无数据。