GCM Values for VM at 20 and

QCM Values forVM at 20 and 25°C. Most GCM values for are based on group definitions that are more discriminative than those used in the models above. Examples are the method of Exner [29] to estimate Vm at 20°C and the method of Fedors [31] to estimate Vm at 25°C. GCM values have been reviewed by van Krevelen [11]. Highly discriminative methods have been developed by Dubois and Loukianoff [32] and by Constantinou et al. [33]. These methods are discussed briefly below. 

LOGIC Method The local-to-global-information-construction (LOGIC) method [32] has been applied to the estimation of the density of alkanes at 25°C. In this method the groups are atom-centered substructures, FRELB (fragment reduced to an 

Code Value Code Value Code Value 

Source Reprinted with permission from Ref. 32. Copyright (1993) Gordon and Breach Publishers, World Trade Center, Lausanne, Switzerland. 

Method of Constantinou, Gani, and O Connell The approach of Constantinou et al. [33] has been described for 77, in Section 9.3. The analog model for V / of liquids at 25°C is 

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