One-particle states

One-particle states are specific conditions describing the presence of a single particle within a quantum system. They encapsulate information about the particle's properties, such as its momentum, energy, and position, in a way that reflects the probabilistic nature of quantum mechanics. Think of them as a precise "profile" of an individual particle that can be used to predict how it will behave or interact with other particles. These states are fundamental to understanding how particles like electrons, photons, or atoms operate at a microscopic level in fields like quantum physics and quantum chemistry.