Greater bond distance for silicon diamond structure than for carbon diamond structure?
Yes, both structures belong to the same diamond cubic type, and the interatomic distances for diamond and silicon (you can use "Measurements" tool from the JSmol menu)

$$
\begin{align}
d(\ce{C-C}) &amp;= \pu{1.54 Å} \\
d(\ce{Si-Si}) &amp;= \pu{2.35 Å} \\
\frac{d(\ce{Si-Si})}{d(\ce{C-C})} &amp;\approx 1.53
\end{align}
$$

are in a good agreement with the corresponding covalent radii

$$
\begin{align}
r_\mathrm{cov}(\ce{C}) &amp;= \pu{0.76 Å} \\
r_\mathrm{cov}(\ce{Si}) &amp;= \pu{1.11 Å} \\
\frac{r_\mathrm{cov}(\ce{Si})}{r_\mathrm{cov}(\ce{C})} &amp;\approx 1.46
\end{align}
$$

which would set the silicon atoms further apart from each other.