Orthonormal Basis Sets and Superposition States for the 1D Quantum Particle in a Box

I created this video to follow my video "Solving the Time-dependent Schrödinger Equation for the 1D Particle in a Box," found here:    • Solving the Time-dependent Schrödinger Equ...   This video is part of my Quantum Mechanics for Physical Chemistry playlist:    • Quantum Mechanics   This supplemental video covers the way solutions to the Schrödinger equation for the 1D particle in a box form an orthonormal basis set, and also how these solutions can be combined into superposition states (linear combinations), which are also solutions to the Schrödinger equation.