Net atomic partial charges

Table 8.4 Net atomic partial charges (au) of key elements from extended Hiickel calculations. Positions are indicated in Figure 8.1. Reproduced by permission of Elsevier, ref. 29.

In this case, Y/tt is a coulomb integral, and and are the net atomic partial charges AGp is the electric polarization part of the free energy of solvation. 

In the version SM5.2PD, the atomic partial charges are taken as the Mulliken-population-analysis net charges (Section 15.6), which are given by Cb - where... 

No, K. T., J. A. Grant, M. S. Jhon, and H. A. Scheraga. 1990. Determination of Net Atomic Charges Using a Modified Partial Equalization of Orbital Electronegativity Method 2. Application to Ionic and Aromatic Molecules as Models for Polypeptides. J. Phys. Chem. 94, 4740-4746. 

In the CPSA approach, the fundamental molecular properties are the surface area contributions of the positively and negatively charged atoms r and s, SAj and SA , and the associated net atomic charges, Q and Q . The simple partial positive surface area (PPSA) is defined as sum of all positively charged surface areas and is called PPSA-1, and the respective partial negative surface area (PNSA) as sum of all negatively charged surface areas is called PNSA-1 ... 

So far, there has been little use of ab initio methods for the derivation of QSARs to predict the toxic potency and mode of action of chemicals. The present results indicate that with regard to net atomic charges and charge partial surface area descriptors, ab initio methods may indeed provide a different type of information, which should be kept in mind for future investigations, particularly when focusing on the charge-controlled impact on bioreactivity of drugs and toxicants. 

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