In this equation, we consider 𝑁 types of physical properties, each with some number 𝑀 𝑛 of measurements for that type. The quantity 𝑦 𝑚 represents the value of the 𝑚th measurement for a physical property type, and the denominator 𝑑 𝑛 is a scaling coefficient for a given property. The scaling coefficients are set so that each physical property type contributes equally to the objective function for OpenFF 1.0.0 , the starting point of our optimizations.