 So we will outline the CNT calculation for the homogeneous nucleation barrier formula_5.To understand if nucleation is fast or slow, formula_42 needs to be calculated.The classical theory assumes that even for a microscopic nucleus of the new phase, we can write the free energy of a droplet formula_43 as the sum of a bulk term that is proportional to the volume of the nucleus, and a surface term, that is proportional to its surface area

The first term is the volume term, and as we are assuming that the nucleus is spherical, this is the volume of a sphere of radius formula_45.