Preface for the Second Edition
vii
namely to explain why the N-N bond of N 2 O 4 is long and weak. (Of course, since
that time, much progress has been made!) I also appreciate greatly the regular
valence-bond interactions that I have with Professors Thomas M. Klapötke (LMU
Munich) and Brian J. Duke (Monash Pharmacy). I am indebted to and thank the
School of Chemistry at the University of Melbourne for its continuous support. I
also thank Springer for inviting me to prepare a 2
nd edition, Dr. Steffen Pauly and
Beate Siek for editorial assistance, and Dr. Angelika Schulz for her patience and
help with the printing of this 2
nd edition, using a now difficult-to-handle 1st edition. Dr. Walter P. Roso provided us with his ab initio valence-bond program.
For this 2
nd edition, I have made only minor modifications to the text for the 1st
edition, and essentially not up-dated its content and references. However I have
included an addendum with a number of the chapters. These addenda, together
with a new chapter, present some of the post-1982 applications of increasedvalence theory. Michael Whitehead drew some of the additional valence-bond
structures. Although other valence-bond researchers almost never use increasedvalence descriptions of electronic structure, I appreciate the significant alternative
contributions to valence-bond theory that these researchers have made. However
because I am presenting essentially the increased-valence approach to electronic
structure, in this volume I refer rarely to their contributions.
Texts on alternative types of valence-bond theory include those of references 1
and 2. Reference 3 provides a review of modern ab initio methods and classical
valence-bond approaches to electronic structure. References 4 and 5 provide
reviews of generalised and spin-coupled valence-bond theory. Both of these
theories can use delocalised orbitals that involve more than two atomic centres to
accommodate the active-space electrons. In references 6-8, overviews are
presented of aspects of increased-valence theory.
1) N.D. Epiotis, “Unified Valence-bond Theory of Electronic Structure”, Lecture
Notes in Chemistry, (Springer-Verlag Berlin Heidelberg New York) Volume
29 (1982) and Volume 34 (1983).
2) S.S. Shaik and P.C. Hiberty, “A Chemist’s Guide to Valence-bond Theory”,
(Wiley-Interscience & Sons, Inc. Hoboken, New Jersey) (2008).
3) W. Wu, P. Su, S. Shaik and P.C. Hiberty, Chem. Revs. 111, 7557-7593
(2011).
4) W.A. Goddard III, T.H. Dunning Jr., W.J. Hunt and P.J. Hay, Acc. Chem.
Res. 6, 368-376 (1973).
5) D.L. Cooper, J. Gerratt and M. Raimondi, Chem. Rev. 91, 929 (1991). See
also the spin-coupled valence-bond chapters in each of Refs. 6(a), (b) and (c)
below.
6) R.D. Harcourt, (a) in “Valence-bond Theory and Chemical Structure” (Delete
H 2
- postscript) (Elsevier Science BV; editors D. Klein and N. Trinajstić)
pp. 251-285 (1990). (b) in “Pauling's Legacy: Modern Modelling of the
Chemical Bond” (Elsevier Science B.V.; editors Z.B. Maksić and W.J.
Orville-Thomas) pp. 449-480 (1999). (c) in “Quantum Chemical Methods in
vii
namely to explain why the N-N bond of N 2 O 4 is long and weak. (Of course, since
that time, much progress has been made!) I also appreciate greatly the regular
valence-bond interactions that I have with Professors Thomas M. Klapötke (LMU
Munich) and Brian J. Duke (Monash Pharmacy). I am indebted to and thank the
School of Chemistry at the University of Melbourne for its continuous support. I
also thank Springer for inviting me to prepare a 2
nd edition, Dr. Steffen Pauly and
Beate Siek for editorial assistance, and Dr. Angelika Schulz for her patience and
help with the printing of this 2
nd edition, using a now difficult-to-handle 1st edition. Dr. Walter P. Roso provided us with his ab initio valence-bond program.
For this 2
nd edition, I have made only minor modifications to the text for the 1st
edition, and essentially not up-dated its content and references. However I have
included an addendum with a number of the chapters. These addenda, together
with a new chapter, present some of the post-1982 applications of increasedvalence theory. Michael Whitehead drew some of the additional valence-bond
structures. Although other valence-bond researchers almost never use increasedvalence descriptions of electronic structure, I appreciate the significant alternative
contributions to valence-bond theory that these researchers have made. However
because I am presenting essentially the increased-valence approach to electronic
structure, in this volume I refer rarely to their contributions.
Texts on alternative types of valence-bond theory include those of references 1
and 2. Reference 3 provides a review of modern ab initio methods and classical
valence-bond approaches to electronic structure. References 4 and 5 provide
reviews of generalised and spin-coupled valence-bond theory. Both of these
theories can use delocalised orbitals that involve more than two atomic centres to
accommodate the active-space electrons. In references 6-8, overviews are
presented of aspects of increased-valence theory.
1) N.D. Epiotis, “Unified Valence-bond Theory of Electronic Structure”, Lecture
Notes in Chemistry, (Springer-Verlag Berlin Heidelberg New York) Volume
29 (1982) and Volume 34 (1983).
2) S.S. Shaik and P.C. Hiberty, “A Chemist’s Guide to Valence-bond Theory”,
(Wiley-Interscience & Sons, Inc. Hoboken, New Jersey) (2008).
3) W. Wu, P. Su, S. Shaik and P.C. Hiberty, Chem. Revs. 111, 7557-7593
(2011).
4) W.A. Goddard III, T.H. Dunning Jr., W.J. Hunt and P.J. Hay, Acc. Chem.
Res. 6, 368-376 (1973).
5) D.L. Cooper, J. Gerratt and M. Raimondi, Chem. Rev. 91, 929 (1991). See
also the spin-coupled valence-bond chapters in each of Refs. 6(a), (b) and (c)
below.
6) R.D. Harcourt, (a) in “Valence-bond Theory and Chemical Structure” (Delete
H 2
- postscript) (Elsevier Science BV; editors D. Klein and N. Trinajstić)
pp. 251-285 (1990). (b) in “Pauling's Legacy: Modern Modelling of the
Chemical Bond” (Elsevier Science B.V.; editors Z.B. Maksić and W.J.
Orville-Thomas) pp. 449-480 (1999). (c) in “Quantum Chemical Methods in