Preface
Energy and mass transfers in chemical processes are an intricate land of adventure
in which atoms and molecules compete and collaborate on different paths in a way
that challenges intellectual abilities when trying to rationalize unexpected
outcomes.
This book has been designed to help the students of the European Erasmus
Mundus Master in “Theoretical Chemistry and Computational Modeling” (TCCM)
to familiarize with both theoretical methods and compute techniques useful to
handle the microscopic nature of chemical processes. Because of this, the level of
references, pseudocodes, and text has been kept as simple and as general as possible
by leveraging on the experience gained by teaching the subject for years at the
home University and at the TCCM intensive course. We have also tried to avoid
misprints and inaccuracies through repeated cross checks. Despite that, the book
might not be free of errors and we ask the readers the favor of letting us know (our
emails are given in the front page) about possible improvements.
In the book, the reader is driven to disentangle elementary events out of the
kinetics of complex systems in which reactive and nonreactive processes combine
and compete in different ways depending on the interactions and momenta of the
species involved. Out of such complexity, we gradually single out and deal with the
key features (by leveraging preferentially on elementary gas phase processes) of
two-, three-, four-, and many-body collisions. Then, complexity is regained to
extend the treatment to large systems by introducing some approximations.
The book starts in chapter one by considering the modeling of rate coefficients in
terms of the transition state (TS) approach. From the analysis of the weakness of the
TS model (useful for a phenomenological systematization of experimental data
although useless for predictions), the efficiency of chemical processes is rationalized in terms of collisions of two structureless bodies using classical mechanics
(in which atoms are considered as mass points) and simple model interactions (like
pure Coulomb attraction and/or repulsion, hard sphere, mixed attraction at long
range plus repulsion at short range (Sutherland, Morse, and Lennard-Jones)).
Classical mechanics computational machinery, relying on both analytical and
numerical procedures tailored to solve related Newton, Hamilton, and Lagrange
vii
Energy and mass transfers in chemical processes are an intricate land of adventure
in which atoms and molecules compete and collaborate on different paths in a way
that challenges intellectual abilities when trying to rationalize unexpected
outcomes.
This book has been designed to help the students of the European Erasmus
Mundus Master in “Theoretical Chemistry and Computational Modeling” (TCCM)
to familiarize with both theoretical methods and compute techniques useful to
handle the microscopic nature of chemical processes. Because of this, the level of
references, pseudocodes, and text has been kept as simple and as general as possible
by leveraging on the experience gained by teaching the subject for years at the
home University and at the TCCM intensive course. We have also tried to avoid
misprints and inaccuracies through repeated cross checks. Despite that, the book
might not be free of errors and we ask the readers the favor of letting us know (our
emails are given in the front page) about possible improvements.
In the book, the reader is driven to disentangle elementary events out of the
kinetics of complex systems in which reactive and nonreactive processes combine
and compete in different ways depending on the interactions and momenta of the
species involved. Out of such complexity, we gradually single out and deal with the
key features (by leveraging preferentially on elementary gas phase processes) of
two-, three-, four-, and many-body collisions. Then, complexity is regained to
extend the treatment to large systems by introducing some approximations.
The book starts in chapter one by considering the modeling of rate coefficients in
terms of the transition state (TS) approach. From the analysis of the weakness of the
TS model (useful for a phenomenological systematization of experimental data
although useless for predictions), the efficiency of chemical processes is rationalized in terms of collisions of two structureless bodies using classical mechanics
(in which atoms are considered as mass points) and simple model interactions (like
pure Coulomb attraction and/or repulsion, hard sphere, mixed attraction at long
range plus repulsion at short range (Sutherland, Morse, and Lennard-Jones)).
Classical mechanics computational machinery, relying on both analytical and
numerical procedures tailored to solve related Newton, Hamilton, and Lagrange
vii