An orthorhombic benzene-silicalite-1 single crystal was obtained from a monoclinic twin crystal, and the structure was determined by a single-crystal method for the first time.

A simple method for preparing monoclinic single crystals of ZSM-5 is developed. The ZSM-5 crystals are pressed with a weight of 50 g at an angle of 45° relative to the b and c crystallographic axes of twin ZSM-5 crystals while the temperature is simultaneously increased to 573 K. The temperature is then slowly reduced to 313 K, and these steps are repeated three times. The monoclinic structure of the single crystals of ZSM-5 produced using this method is then determined.