HDSA1 - hydrogen bonding donor ability
TMSA - total molecular surface area
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.