Going with the flow

Molecular models for fluids 

Klaus Lucas 

Cambridge, UK: Cambridge University Press  | 2007 | 406 pp | ?55.00 (HB) | ISBN 9780521852401 

Reviewed by Martin Sweatman

This ambitious book explains how the thermodynamic properties of fluids are linked to the underlying quantum mechanics of atoms and molecules. The text is generally clear and supported by numerous useful worked examples. Ultimately, the properties of single molecules can be predicted quite accurately on this basis, but one should look to empirical, or classical, models if one is interested in predicting the vapour-liquid coexistence of mixtures, as many chemical engineers are. 

Apparently, techniques based on PC-SAFT are the best one can do in this case, and then only for small or fully flexible molecules. So what was all the fuss about quantum mechanics anyway - and would I recommend this book to my postgraduate students? 

Actually I would. It makes a much-needed contribution to the modernisation of chemical engineering, where the link between microstate and macrostate is emphasised in terms of statistical mechanics. And, even if the quantum mechanical basis for equations of state of pure fluids is eventually lost, at least the formal link is laid out and arguments for the empirical route are well made. The quantum mechanical background is still useful when developing mixing rules.  

Ultimately, my only gripe is the bias against density functional theory. Quantum DFT gets short shrift, while its classical cousin isn’t mentioned at all, despite its strong connections with equations of state. Instead, we are treated to an entire chapter of excess function models, which are rooted in more traditional chemical engineering. I find it a shame that this valuable field is neglected. As a result I would expect chemical engineers to find this book more interesting than physicists.