Why the bond angle in solid phase of `H_(2)O_(2)`is reduced when compared to as phase of  `H_(2)O_(2)`?

Explanation

Both the gas phase and solid phase, `H_(2)O_(2)` adopt a skew configuration due to the repulsive interaction of the OH bonds with lone pairs of electrons on each oxygen atoms. Indeed, it is the smallest molecule known to show hindered rotation about a single bond. In the solid phase, the dihedral angle is sensitive and hydrogen bonding decreases from 111.5° in the gas phase to `90.2^(@)` in the solid-phase.