Chapter 15
What Can Be Learnt from a Location
of Bond Paths and from Electron Density
Distribution
Sławomir J. Grabowski
Abstract A bond path being a line of maximum electron density linking attractors
of two atoms is often applied in various studies as a criterion of the existence of
numerous interactions such as for example hydrogen, halogen or pnicogen bond. It
covers cases of atom-atom energetically stabilized links, from weak van der Waals
interactions, through stronger Lewis acid–Lewis base interactions up to covalent
bonds. The location of bond paths also allows interpreting mechanisms of interactions and, in general, of chemical reactions. The Quantum Theory of Atoms in
Molecules (QTAIM) results are mainly presented here; however they are supported
by other approaches as, for example, the Natural Bond Orbitals (NBO) method or
the σ-hole concept. The most important orbital-orbital interactions determined from
the NBO method and characterizing different types of interactions are presented.
The analysis of the distribution of the electron charge density is also performed here
for numerous systems; this is shown that the regions of the concentration and
depletion of the electron density coincide with the regions of the negative and
positive regions of the electrostatic potential. The role of the analysis of the
laplacian of the electron density is shown on the basis of numerous interactions.
Keywords Bond path Á Bond critical point Á Laplacian of the electron density Á
Hydrogen bond Á Halogen bond Á Pnicogen bond Á Lewis acid–Lewis base interaction Á Quantum Theory of Atoms in Molecules (QTAIM) Á Natural Bond Orbitals
(NBO) method Á σ-hole concept Á Electrostatic potential
S.J. Grabowski (&)
Kimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU, and Donostia
International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi, Spain
e-mail: s.grabowski@ikerbasque.org
S.J. Grabowski
Basque Foundation for Science, IKERBASQUE, Maria Diaz de Haro 3,
48013 Bilbao, Spain
© Springer International Publishing Switzerland 2016
R. Chauvin et al. (eds.), Applications of Topological Methods
in Molecular Chemistry, Challenges and Advances in Computational
Chemistry and Physics 22, DOI 10.1007/978-3-319-29022-5_15
399
What Can Be Learnt from a Location
of Bond Paths and from Electron Density
Distribution
Sławomir J. Grabowski
Abstract A bond path being a line of maximum electron density linking attractors
of two atoms is often applied in various studies as a criterion of the existence of
numerous interactions such as for example hydrogen, halogen or pnicogen bond. It
covers cases of atom-atom energetically stabilized links, from weak van der Waals
interactions, through stronger Lewis acid–Lewis base interactions up to covalent
bonds. The location of bond paths also allows interpreting mechanisms of interactions and, in general, of chemical reactions. The Quantum Theory of Atoms in
Molecules (QTAIM) results are mainly presented here; however they are supported
by other approaches as, for example, the Natural Bond Orbitals (NBO) method or
the σ-hole concept. The most important orbital-orbital interactions determined from
the NBO method and characterizing different types of interactions are presented.
The analysis of the distribution of the electron charge density is also performed here
for numerous systems; this is shown that the regions of the concentration and
depletion of the electron density coincide with the regions of the negative and
positive regions of the electrostatic potential. The role of the analysis of the
laplacian of the electron density is shown on the basis of numerous interactions.
Keywords Bond path Á Bond critical point Á Laplacian of the electron density Á
Hydrogen bond Á Halogen bond Á Pnicogen bond Á Lewis acid–Lewis base interaction Á Quantum Theory of Atoms in Molecules (QTAIM) Á Natural Bond Orbitals
(NBO) method Á σ-hole concept Á Electrostatic potential
S.J. Grabowski (&)
Kimika Fakultatea, Euskal Herriko Unibertsitatea UPV/EHU, and Donostia
International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi, Spain
e-mail: s.grabowski@ikerbasque.org
S.J. Grabowski
Basque Foundation for Science, IKERBASQUE, Maria Diaz de Haro 3,
48013 Bilbao, Spain
© Springer International Publishing Switzerland 2016
R. Chauvin et al. (eds.), Applications of Topological Methods
in Molecular Chemistry, Challenges and Advances in Computational
Chemistry and Physics 22, DOI 10.1007/978-3-319-29022-5_15
399