NICE: A Theory-Grounded Diagnostic Benchmark for Social Intelligence of LLMs. - Yunjin Qi; Zhaojun Jiang; Xuan Wu; Hanxi Pan; Yixuan Wang; Yanfang Liu; Xiang Ji; Churu Yu; Chunyuan Zheng; Yingze Chen; Jie He; Liuqing Chen; et al. (CoRR, 2026)