Broadband optical spectroscopy is used to obtain optical spectra of RCd₃P₃ (R: Ce or La), which exhibit a Fermi-liquid behavior with a very low charge carrier density. Notably, our first-principles calculations suggest that subtle displacements of Cd1 and P1 atoms within the unit cell can induce a semiconductor-to-metal transition, emphasizing the sensitivity of electronic structures to atomic positioning. The temperature-dependent anomalies of infrared-active phonons suggest a structural phase transition in these compounds. Our findings will offer a fundamental understanding of structural distortions leading to electronic transitions, which may be relevant for broader applications in correlated electron systems.
- Jaekyung Jang
- Yu-Seong Seo
- Jungseek Hwang
