As a first example, let us discuss the symmetry breaking in the isolated ammonia molecule, NH3. For each rotational and translational state, the nitrogen atom can be above or below the plan formed by the hydrogen atoms (see Figure ). The lowest energy state of a single isolated ammonia molecule  + is a symmetric superposition of these two pyramidal states 1 2 up down (10) We can estimate the Diósi-Penrose time of this system by directly evaluating its gravitational selfenergy with (6). To do so, we need the mass distribution of states up and down . To get them, we first optimized NH3 up-pyramidal ground state geometry. (Here, we did it with density functional theory using the B3LYP functional 39 and the 6-311G(d,p) basis set. 40 For a more advanced discussion of NH3 geometry, see ref. 41 ) The down-pyramidal geometry is obtained by a simple symmetry transformation. Additionally, we must translate both to ensure that their center of mass coincides. Gaussian standard deviation RN = (2) -1/2 is 0.09 Å. In the case of the hydrogen nucleus (proton), it is 0.17 Å. However, we should be careful when interpreting this result. 47 It does not mean that the nuclei have this actual size. If they are measured, they collapse into their standard femtometer scales. A better way to interpret the distribution plotted in Figure is to consider that each dot forming the nitrogen cloud corresponds to a single set of dots in each of the three hydrogen clouds. We cannot pick the dots from each nuclear cloud independently. Now that we have a Gaussian representation of the nuclei, the application of ( ) is straightforward.