Chapter 18
A Complete NCI Perspective: From New
Bonds to Reactivity
Christophe Narth, Zeina Maroun, Roberto A. Boto,
Robin Chaudret, Marie-Laure Bonnet, Jean-Philip Piquemal
and Julia Contreras-García
Abstract The Non-Covalent Interaction (NCI) index is a new topological tool that
has recently been added to the theoretical chemist’s arsenal. NCI fills a gap that
existed within topological methods for the visualization of non-covalent interactions. Based on the electron density and its derivatives, it is able to reveal both
attractive and repulsive interactions in the shape of isosurfaces, whose color code
reveals the nature of the interaction. It is interesting to note that NCI can even be
calculated at the promolecular level, making it a suitable tool for big systems, such
as proteins or DNA. Within this chapter we will review the main characteristics of
NCI, its similarities with and differences from previous approaches. Special
attention will be paid to the visualization of new interaction types. Being based on
the electron density, NCI is not only very stable with respect to the calculation
method, but it is also a suitable tool for detecting new bonding mechanisms, since
all such mechanisms should have a detectable effect on the electron density. This
type of approach overcomes the limitations of bond definition, revealing all
C. Narth Á R.A. Boto Á J.-P. Piquemal Á J. Contreras-García
Laboratoire de Chimie Théorique, UPMC Univ Paris 06, UMR 7616, 75005 Paris, France
e-mail: christophe.narth@lct.jussieu.fr
R.A. Boto
e-mail: alboto@lct.jussieu.fr
J.-P. Piquemal
e-mail: jpp@lct.jussieu.fr
C. Narth Á R.A. Boto Á J.-P. Piquemal Á J. Contreras-García (&)
Laboratoire de Chimie Théorique, CNRS, UMR 7616, 75005 Paris, France
e-mail: contrera@lct.jussieu.fr
Z. Maroun
Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100
Copenhagen, Denmark
e-mail: zeina@chem.ku.dk
Zeina Maroun can be contacted at zema@topsoe.dk
© 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_18
491
A Complete NCI Perspective: From New
Bonds to Reactivity
Christophe Narth, Zeina Maroun, Roberto A. Boto,
Robin Chaudret, Marie-Laure Bonnet, Jean-Philip Piquemal
and Julia Contreras-García
Abstract The Non-Covalent Interaction (NCI) index is a new topological tool that
has recently been added to the theoretical chemist’s arsenal. NCI fills a gap that
existed within topological methods for the visualization of non-covalent interactions. Based on the electron density and its derivatives, it is able to reveal both
attractive and repulsive interactions in the shape of isosurfaces, whose color code
reveals the nature of the interaction. It is interesting to note that NCI can even be
calculated at the promolecular level, making it a suitable tool for big systems, such
as proteins or DNA. Within this chapter we will review the main characteristics of
NCI, its similarities with and differences from previous approaches. Special
attention will be paid to the visualization of new interaction types. Being based on
the electron density, NCI is not only very stable with respect to the calculation
method, but it is also a suitable tool for detecting new bonding mechanisms, since
all such mechanisms should have a detectable effect on the electron density. This
type of approach overcomes the limitations of bond definition, revealing all
C. Narth Á R.A. Boto Á J.-P. Piquemal Á J. Contreras-García
Laboratoire de Chimie Théorique, UPMC Univ Paris 06, UMR 7616, 75005 Paris, France
e-mail: christophe.narth@lct.jussieu.fr
R.A. Boto
e-mail: alboto@lct.jussieu.fr
J.-P. Piquemal
e-mail: jpp@lct.jussieu.fr
C. Narth Á R.A. Boto Á J.-P. Piquemal Á J. Contreras-García (&)
Laboratoire de Chimie Théorique, CNRS, UMR 7616, 75005 Paris, France
e-mail: contrera@lct.jussieu.fr
Z. Maroun
Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100
Copenhagen, Denmark
e-mail: zeina@chem.ku.dk
Zeina Maroun can be contacted at zema@topsoe.dk
© 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_18
491