Nonatomic sites

Both rms and rrms are sensitive to the choice of grid point locations where the QM potential is evaluated. Typical values of rms and rrms are 1 to 3 kJ/mol and 3 to 9% with 6-3IG" wavefunctions. The fit generally worsens as grid points are placed closer to the molecule. In certain cases (e.g., strong lone pair effect) worse fits may be obtained with net atomic charge models. Models utilizing additional nonatomic sites, site dipoles, and/or quadrupoles usually give a much better fit. 

Potential-Derived Monopole Models with Additional Nonatomic Sites 249... 

POTENTIAL-DERIVED MONOPOLE MODELS WITH ADDITIONAL NONATOMIC SITES... 

Monsanto Enviro-Chem under the Dyna-Wave trademark case histories can be downloaded from a web site (http //www.enviro-chem. com/airpol/common/rjstop.html). Nonatomizing froth scrubbing is described in those patents as occuring within defining boundaries on a new dimensionless velocity versus dimensionless liquid/gas ratio two-phase flow regime map, shown here as Fig. 17-51. 

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