Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Input: A modification of this procedure adds a position term for the center of mass and requires placing the whole system in a potential sphere in order to use the particle in a box method; that procedure is partially named for Huang. The energy calculated in this procedure is a lower bound on the total energy, and the first step of this procedure finds the energy eigenvalue in terms of the position vector R, creating a potential energy surface. A simple application of it is to find the molecular orbitals of an H-two-plus atom, and its second step involves removing the off-diagonal kinetic energy terms, which creates a set of uncoupled motion equations. It states that the one particle only sees the Coloumb potential of another, which removes several terms from an otherwise hairy partial differential equation. For 10 points, name this method which says that nuclear motion can be ignored when modeling a molecule, named for two guys.
Output:
Science