In CPCM, the reaction potential generated by the solute charge distribution is described in terms of an apparent surface charge (ASC) distribution spread over the solute cavity surface. Outside the surface is a dielectric continuum with a dielectric constant e, whereas the cavity containing the solute has a unit dielectric constant. The cavity boundary is usually discretized into M surface segments (tesserae) with ASCs, { 𝑞 ! " }, that describe the electric field of the polarized continuum.