Author(s): Ying Song, Lingzhi Cao, Jinming Zhai, Zhilong Yang, Yali Yang, Laurent Bellaiche, and Jiangang He ${\mathrm{AgNbO}}_{3}$ is a lead-free perovskite with considerable potential for energy storage and optoelectronic applications, yet its low-temperature crystal structure has remained controversial. In this Letter, we revisit its low-energy structural landscape using a systematic first-principles st… [Phys. Rev. Lett. 137, 036102] Published Fri Jul 17, 2026