Photoelectron imaging is a technique used in the field of physical chemistry to study the properties of molecules and atoms by measuring the energies and angular distributions of photoelectrons ejected from the sample upon absorption of ultraviolet or X-ray photons. This technique provides valuable information about the electronic structure, geometry, and dynamics of molecules, allowing researchers to understand chemical reactions, molecular structures, and bonding interactions in detail. Photoelectron imaging is often used in combination with other spectroscopic techniques to provide a comprehensive picture of the properties of molecules and atoms.