The atoms in a molecular covalent structure are held together as molecules by strong covalent bonds. There are weak intermolecular forces between different molecules. These weak forces are called van ...

School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, U.K.

School of Civil Engineering and Architecture, Henan University, Kaifeng, Henan 475004, People’s Republic of China ...