What is intermolecular distance in water?
Not all data are provided in explicit form. They are often not frequently needed and can be often deduced from other data with using of high school knowledge.
You can calculate the volume occupied by 1 water molecule ( in average ) from the water molar mass $\pu{M}$, water density $\pu{\rho}$ and the Avogadro constant $N_\mathrm{A}$ as
$$V=\dfrac{M}{\rho \cdot N_\mathrm{A}} $$
Then you can calculate the side length $a$ of a cube of this volume:
$$a={\left( \dfrac{M}{\rho \cdot N_\mathrm{A}}  \right)}^{1/3}  $$
As a rough number, is is equal to
$a  \approx { \left( \dfrac{\pu{0.018 kgmol^-1}}{\pu{1000 kgm^-3} \cdot \pu{6.022e23 mol^-1}}  \right)}^{1/3}  \approx \pu{0.31 nm}$
what can be taken as the typical &quot;center to center&quot; distance of water molecules within the order-like rough precision.
The more precise average distance would have to calculate with the size and shape of the water molecule ( $\ce{O-H}$ bond length about 0.096 nm, the bond angle 104.5 degrees) and to make the integral average over the directions. But it would be extremely complicated, considering also difficulties with molecule borders and hydrogen bonds. In some sense can be said the distance is zero or even &quot;negative&quot;, as the molecules form bonds ands overlaps.