Gasteiger-Marsili approach

The Gasteiger-Marsili approach uses the concept of the partial equalisation of orbital electronegativity. Electronegativity is a concept well known to chemists, being defined by Pauling as the power of an atom to attract electrons to itself. Mulliken subsequently defined the electronegativity of an atom A as the average of its ionisation potential and its electron affinity E ... 

The first term in Eqs. [28]-[31] is related to hydrophobicity, whereas hydrophilicity is encoded by the others terms. The third term in Eqs. [30] and [31] is introduced to incorporate effects of molecular polarizability. Calculations of partition coefficients for 90 model compounds indicate that Eq. [30] is the best one and that a fast and cheap method to calculate atomic charges (e.g., the Gasteiger-Marsili approach>26) is perfectly adequate. The accuracy obtained with Eq. [30] is comparable to that reported by Bodor et al. 29,i3o addition, this method yields distinct values for geometric isomers or different conformers of flexible compounds, indicating that it is able to determine the influence of 3D arrangements of atoms on the overall lipophilic character of a structure. 

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