StellarPotential Energy vs. Distance Between Atoms
At higher distances, the atoms experience little interaction, so the potential energy is near zero. As they get closer, they attract, lowering the potential energy and reaching a minimum at the bond length. If the atoms get too close, repulsive forces push against each other, sharply increasing potential energy. Usually, the stronger the bond is the shorter its length is, so triple bonds are shorter than double bonds which are shorter than single bonds.