Total charge weighted partial positively charged surface area

Definition:

S_A - positively charged solvent-accessible atomic surface area

q_A - atomic partial charge

Reference:

1. D.T. Stanton, P.C. Jurs, Anal. Chem., 1990, 62, 2323 .; D.T. Stanton, L.M. Egolf, P.C. Jurs, M.G. Hicks, J. Chem. Inf. Comput. Sci., 1992, 32, 306 .