| Summary: | A thorough investigation of the structural parameters of micromechanically exfoliated multilayer WSe<sub>2 </sub>flakes was undertaken between 400 K to 110 K. Crystal structure of WSe<sub>2</sub> remains in the trigonal prismatic structure in this temperature range, however, with a clear difference in the temperature dependence of the in-plane <em>a</em>, and the out-of-plane <em>c</em>, lattice parameters. The linear coefficients of thermal expansion of <em>a</em> and <em>c</em> are 5.132 × 10<sup>−6</sup>/K and 8.105 × 10<sup>−6</sup>/K, respectively. The temperature dependence of the unit-cell volume is analyzed using zero-pressure equation-of-state which yielded the Debye temperature of the WSe<sub>2 </sub>to be 160 K. Following the temperature dependence of the W-Se and W-W bond distances, a nonlinear behavior is observed in the former in contrast to a rather regular behavior of the later. This significant difference in the temperature dependence of the <em>a</em> and <em>c</em> lattice parameters can have consequences in the macroscopic physical properties of the system. A good correlation between the temperature dependence of the W-Se bond distance and Raman E<sup>1<sub>2g</sub></sup> mode has been observed.
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