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We report here the first results from a Fourier transform infrared (FTIR) and density functional theory (DFT) study on SiC$\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}$. This species has been produced by ablating a rod made of silicon and graphite powder with a Nd:YAG laser and trapping the products in solid Ar at $\sim$ 15 K. In the only previous observation of SiC$\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}$, McCarthy \textit{et al}. reported the microwave rotational spectrum nderline{\textbf{538}}, 766 (2000)}. In the present work, extensive FTIR measurements of vibrational frequencies and isotopic shifts from $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}$C enrichment and the naturally occurring $\mathrm{<mrow\; data-mjx-texclass="ORD">29,30</mrow>}$Si isotopes have been compared with the predictions of density functional theory calculations at the B3LYP/cc-pVDZ level. The excellent agreement between experiment and theory has enabled the assignment of the $\nu 4(\sigma )$ fundamental of linear SiC$\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}$ at 936.9 $\pm$ 0.2 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$. This information may help in identifying SiC$\mathrm{<mrow\; data-mjx-texclass="ORD">5</mrow>}$ in circumstellar and interstellar environments.