Description:
<jats:title>Abstract</jats:title><jats:p>Zone‐center optical phonons in ZrSe<jats:sub>3</jats:sub>, the prototype of the IV<jats:sub>B</jats:sub>‐trichalcogenides family, are investigated by Raman scattering for several incident and scattered light polarizations, and by infrared reflectance measurements. These layered compounds are characterized by isolated chains along the <jats:italic>b</jats:italic>‐monoclinic axis formed by the linear stacking of distorted trigonal prisms with Se atoms at the corners and Zr atoms in the center. Nine modes are found among the twenty‐ones theoretically predicted. Phonons assignment is made by a group theoretical analysis of the crystal structure, using the correlation method which relates single chain modes to crystal modes as the interchain coupling is truned on.</jats:p>