collision cross section

Collision cross section (CCS) is a measurement that describes the size and shape of a molecule as it interacts with a gas. Imagine it as the apparent "target area" a molecule presents when speeding through a gas; larger or more extended molecules have higher CCS, while smaller or more compact ones have lower CCS. It helps scientists identify and differentiate molecules based on how they behave in a gas phase, especially in techniques like ion mobility spectrometry. Essentially, CCS provides insight into a molecule’s structure and shape by quantifying how it collides with surrounding gas molecules during analysis.