Dear Mostafa,

It is based on my experience, I found this is a meaningful threshold by studying ESP of many representative molecules.

More discussion can be found in my blog article: //www.umsyar.com/518 (written in Chinese)

Best,

Tian

Dear Multiwfn developers,
I've been using the electrostatic potential analysis to calculate the surface areas for some conformations. According to the output, the polar and nonpolar areas are defined based on the absolute value of ESP:

Nonpolar surface area (|ESP| <= 10 kcal/mol):
Polar surface area (|ESP| > 10 kcal/mol):

I'm wondering if this default ESP energy threshold (10 kcal/mol) is based on your experience or the studies in the literature.
Thank you very much.

Best,
Mostafa