Dihedrallike

Dihedrallike is a term used in computational chemistry and materials science to describe a molecular or structural arrangement that approximates a dihedral angle, but with certain constraints or modifications. A standard dihedral angle describes the rotation around a bond between two atoms, defined by the relative orientation of two intersecting planes. The "dihedrallike" concept extends this by considering situations where the ideal, lowest-energy dihedral conformation might not be perfectly achieved due to steric hindrance, electronic effects, or the presence of multiple interacting forces within a larger molecular system or crystal lattice.

This term is particularly relevant when analyzing protein structures, where amino acid side chains adopt specific dihedral angles to achieve their functional conformations. However, local environmental factors, such as interactions with neighboring residues or the surrounding solvent, can lead to "dihedrallike" arrangements that deviate slightly from the energetically preferred isolated dihedral angle. Similarly, in the study of molecular crystals or polymeric materials, the packing of molecules can force dihedral angles into non-ideal orientations. The term implies that the system is still largely governed by the principles of dihedral rotation, but the specific angle observed is a compromise dictated by external influences. Understanding dihedrallike conformations is crucial for accurately predicting molecular properties, reaction pathways, and material behavior.