Abbreviations
bcp
Bond critical point
BP
Bond path
CP
Critical point
DI
Delocalization index
ED
Electron density
FHDD Fermi Hole Delocalization Density index
HOMA Harmonic Oscillator Model of Aromaticity
LS
Local Source Function
MO
Molecular Orbital
NBCC Non Bonded Charge Concentration
NICS
Nucleus-Independent Chemical Shift
QTAIM Quantum Theory of Atoms in Molecules
PAH
Polycyclic Aromatic Hydrocarbons
PDI
Para-Delocalization Index
rp
Reference point
SDD
Electron Spin Density Distribution
SF
Source Function (for the electron density)
SF S
Source Function (for the electron spin density)
SF%
Percentage Source Function (for the electron density)
SF S %
Percentage Source Function (for the electron spin density)
SFLAI Source Function Local Aromaticity Index
3MR
Three-Membered Ring
6MR
Six-Membered Ring
7MR
Seven-Membered Ring
10MR
Ten-Membered Ring
5.1 Introduction
This chapter highlights recent developments and new applications of the Source
Function (SF) descriptor, introduced long time ago by Bader and Gatti [1] and later
on largely used in several studies (for comprehensive and critical overviews,
updated to 2012, see Refs. [2, 3]). The SF enables one to see the properties of a
scalar at a given point of the space in terms of source contributions from all other
points of the space, within an interesting cause-effect relationship. It represents,
therefore, a tool profoundly germane to one of the main operative notions of
chemistry, that is that any local property and chemical behaviour of a system is to
some extent, be it small or large, influenced by the remaining parts of the system. It
is also neatly connected to the Topological methods in molecular chemistry, one of
the main focus of the present book, as the SF relates a local property of a scalar of
interest to chemistry, say the electron density, to its local source behaviour in
another, far or close, region of space. Analysing such a link between the properties
102
C. Gatti et al.
bcp
Bond critical point
BP
Bond path
CP
Critical point
DI
Delocalization index
ED
Electron density
FHDD Fermi Hole Delocalization Density index
HOMA Harmonic Oscillator Model of Aromaticity
LS
Local Source Function
MO
Molecular Orbital
NBCC Non Bonded Charge Concentration
NICS
Nucleus-Independent Chemical Shift
QTAIM Quantum Theory of Atoms in Molecules
PAH
Polycyclic Aromatic Hydrocarbons
PDI
Para-Delocalization Index
rp
Reference point
SDD
Electron Spin Density Distribution
SF
Source Function (for the electron density)
SF S
Source Function (for the electron spin density)
SF%
Percentage Source Function (for the electron density)
SF S %
Percentage Source Function (for the electron spin density)
SFLAI Source Function Local Aromaticity Index
3MR
Three-Membered Ring
6MR
Six-Membered Ring
7MR
Seven-Membered Ring
10MR
Ten-Membered Ring
5.1 Introduction
This chapter highlights recent developments and new applications of the Source
Function (SF) descriptor, introduced long time ago by Bader and Gatti [1] and later
on largely used in several studies (for comprehensive and critical overviews,
updated to 2012, see Refs. [2, 3]). The SF enables one to see the properties of a
scalar at a given point of the space in terms of source contributions from all other
points of the space, within an interesting cause-effect relationship. It represents,
therefore, a tool profoundly germane to one of the main operative notions of
chemistry, that is that any local property and chemical behaviour of a system is to
some extent, be it small or large, influenced by the remaining parts of the system. It
is also neatly connected to the Topological methods in molecular chemistry, one of
the main focus of the present book, as the SF relates a local property of a scalar of
interest to chemistry, say the electron density, to its local source behaviour in
another, far or close, region of space. Analysing such a link between the properties
102
C. Gatti et al.