Table 1. Definitions of integral quantities of the ESP, integrated over isosurfaces of the electron density according to Politzer et al. (2001 ▸).

Symbol	Description
	Percentage of surface area with positive ESP
	Percentage of surface area with negative ESP
	Average ESP, averaged over positive regions of the ESP
	Average ESP, averaged over negative regions of the ESP
	Average ESP, averaged over the entire surface
	Minimum value of the ESP on the surface
	Maximum value of the ESP on the surface
	Difference between maximum and minimum values of the ESP on the surface
Π	Average deviation of the ESP from its average value
	Variance of the ESP over its positive regions
	Variance of the ESP over its negative regions
	Sum of positive and negative variances of the ESP
ν	Degree of the electrostatic balance derived from the variances of the ESP