For 10 points, name this quantum system in which an object is trapped in a square container.
Using this system to model solvated electrons in a solution of lithium in ammonia correctly derives the wavelength of said solution's color. Modeling an alpha particle in a nucleus as this system leads to the Geiger-Nuttall formula. Assuming a deep well in the quantum-confined Stark effect allows the estimation of its energies by treating it as this system, while an iterated version of this system in one dimension gives the Kronig-Penny model. The square root of 2 over L is the normalizing constant for this system, whose energy levels correspond to n squared h squared over 8 m L. For 10 points, name this quantum system in which an object is trapped in a square container.
Using this system to model solvated electrons in a solution of lithium in ammonia correctly derives the wavelength of said solution's color.
 Particle in a Box [or [in]finite Potential Well; or Square Well; or Rectangular well]