Theoretical masses refer to the calculated masses of atoms, molecules or particles in a hypothetical scenario. In scientific research, theoretical masses are often used to predict the behavior of matter in various scenarios or reactions before they are tested in experiments. To refer to these theoretical masses, one can use various synonyms such as calculated masses, predicted masses or expected masses. Another way to describe theoretical masses is to use the phrase computed masses. In some cases, these masses can also be referred to as estimated masses or approximate masses, depending on the level of precision or certainty in the calculations.