Advances in Quantum Chemical Topology Beyond QTAIM

Advances in Quantum Chemical Topology Beyond QTAIM
Copyright
Contributors
Photochemistry: A topological perspective
Introduction
Excitation of the ground state
Deactivation mechanisms of excited states
Theory
Polarization
Theory of transition probabilities
QTAIM-photochemistry
Polarizabilities and transition probabilities
QTAIM applications in photochemistry
Alternative topological approaches
Stress tensor
Final comment
References
Introduction to QTAIM and beyond
Introduction
QTAIM
The electron density topology
Descriptor functions and the chemical bond
Integrated or atomic properties
Attractors and basins: Canonical QTAIM atom
Beyond QTAIM
Mathematical fundamentals of QTAIM
Definition of an atom
Hard-Wall atoms and QTAIM
The Bader-stationary action: A proper quantum subsystem
References
An introduction to quantum chemistry
What is quantum chemistry?
The molecular equation
The Born-Oppenheimer approximation
The electronic structure problem
Determination of the many-electron wave-function
Beyond a single determinant
Density functional theory
Solution of the Kohn-Sham equations
The nuclear problem
Potential energy surfaces
The Hellmann-Feynman theorem and molecular stability
Geometry optimization
Quantum chemistry software packages
Concluding remarks
References
New high-performance QTAIM algorithms: From organic photovoltaics to catalyst materials
Introduction
QTAIM standard algorithms/software
New generation of high-performance QTAIM algorithms
QTAIM real-world applications
Organic photovoltaics
Nanostructures as wires
Catalyst materials
Conclusions
References
Structural and bond evolutions during a chemical reaction
Introduction
Energetic evolution
Geometry and structure
Catastrophe theory
Structural evolution and chemical change
Evolution of electron density
Evolution of the Laplacian of electron density
Electron localization function and its evolution
Evolution of the molecular electrostatic potential
Reaction evolution in terms of integrated properties
Local vs. integrated properties
Localization and delocalization indices
IQA analysis and chemical reactions
Force analysis of chemical processes
Perspectives
Bibliography
The MC-QTAIM: A framework for extending the ``atoms in molecules´´ analysis beyon
Introduction
Revealing AIM beyond purely electronic systems
AIM as conceived within the QTAIM
AIM beyond purely electronic systems
AIM as conceived in the MC-QTAIM
AIM properties beyond purely electronic systems
AIM properties as conceived within the QTAIM
AIM properties as conceived within the MC-QTAIM
Conclusion
Acknowledgments
References
Theory developments and applications of next-generation QTAIM (NG-QTAIM)
The vector-based perspective of chemical bonding
Historical context
The need for a non-scalar, physics-based perspective of chemical bonding
Overview of the basic NG-QTAIM concepts
Origins of the NG-QTAIM bond-path framework set B
Theory background: Construction of the NG-QTAIM bond-path framework set B
The construction of NG-QTAIM 3-D bond-path framework set B={p,q,r}
Applications of the bond-path framework set B: Bonding environments and structural preferences
The excited state photochemical reaction path from benzene to benzvalene
The role of the natural transition orbital density in the S0S1 and S0S2 transitions of fulvene
The excited state deactivation reaction of fulvene
Halogen and hydrogen bonding in halogenabenzene/NH3 complexes compared
The directional bonding of [1.1.1] propellane
Stress tensor eigenvector following method for ethene
The role of hydrogen bonding in the structural preferences of small molecule conformers
Factors influencing the relative stability of the S1/S0 conical intersections of the penta-2,4-dieniminium cation ...
Applications of the bond-path framework set B: Ehrenfest force F(r) and the stress tensor σ(r)
Explanation of the unusual strength of the hydrogen-bond in small water clusters
3-D bond-paths of QTAIM and the stress tensor in neutral lithium clusters, Lim (m=2-5), presented on the Ehrenfest ...
Applications of the NG-QTAIM bond-path framework set B: Molecular devices, switches, wires and ring-opening reactions
Predicting competitive and noncompetitive torquoselectivity of thermal ring-opening reactions
The design of quinone-based switches with hydrogen tautomerization
Scoring molecular wires in electric-fields for molecular electronic devices
Results and discussion
Summary
The dihydrocostunolide (DHCL) photochemical ring-opening reaction
The cyclohexadiene (CHD) photochemical ring-opening reaction of cyclohexadiene (CHD)
The NG-QTAIM bond-path precession K
Theory background: The NG-QTAIM bond-path precession K
Applications of the bond-path precession K: Excited states
Bond-path-rigidity and bond-path-flexibility of the excited state deactivation reaction Fulvene
Applications of the bond-path precession K: Normal modes
Bond flexing, twisting, anharmonicity and responsivity for the IR-active modes of benzene
Results and discussions
Summary
Applications of the bond-path precession K: Switches
Fatigue and fatigue resistance in S1 excited state Diarylethenes in electric fields
The NG-QTAIM Uσ-space stress tensor trajectory Tσ(s)
Theory background: The NG-QTAIM Uσ-space stress tensor trajectory Tσ(s)
Applications of the stress tensor trajectory Tσ(s): Bonding environments and structural preferences
The Uσ-space trajectories of the four infrared active normal modes of benzene
A stress tensor eigenvector projection space for the (H2O)5 potential energy surface
Applications of the stress tensor trajectory Tσ(s): Molecular devices: Switches and molecular rotary motors
Fatigue and photochromism S1 excited state reactivity of diarylethenes
The CO ring-opening photo-reactions of oxirane with the Ehrenfest force F(r) trajectories
Quinone-based switches for candidate building blocks of molecular junctions
The dynamics trajectories of a light-driven rotary molecular motor
Applications of the stress tensor trajectory Tσ(s): Isoenergetic phenomena: Stereoisomers
The chirality-helicity equivalence in the S and R stereoisomers of lactic acid and alanine
Comparison of QTAIM and the stress tensor for the chirality-helicity equivalence in S and R stereoisomers
Applications of the stress tensor trajectory Tσ(s): Isoenergetic phenomena: Competitive ring-opening reactions, isot ...
Distinguishing and quantifying the torquoselectivity in competitive ring-opening reactions
A non-scalar approach to the intramolecular mode coupling of the isotopomers of water
The tunneling pathways of the flip rearrangements between permutation-inversion isomers of (H2O)5
Summary, future outlook and suggestions for further work
Summary
Active control of molecular devices
Prediction of asymmetric synthetic reactions
Acknowledgments
References
Real-space description of molecular processes in electronic excited states
Introduction
Charge distribution of electronic excited states
Electron density differences
Formaldehyde in the S1 state
Excimer formation
Intermolecular interactions in the (C6H6)2* and (C10H8)2* excimers
Bonding properties of excimers of He2 in singlet electronic states
Atomic multipole moments
Multipole moments of CO
Photochromism in the water excimer
Excited-state aromaticity
Aromaticity of polycyclic arenes
Excited-state intramolecular proton transfer of salicylideneaniline
Conical intersection of hypoxanthine
Interacting quantum atoms
Applications
Electronic absorption
Bond formation in excited states
Avoided crossing of states in LiF
Conical intersections in C2H4
Photodissociation of cyclobutane
Conclusions
One- and two-electron densities matrices
Configuration interaction methods
MRCI-SD
CASPT2
EOM-CCSD
Acknowledgments
References
Open quantum systems, electron distribution functions, fragment natural orbitals, and the quantum theory of at ...
Introduction
Open quantum systems
Sector density operators for SDW
Sector density operators for multideterminant wave functions
Using orthogonal spin-orbitals in A, B, and R3
Single-determinant wave functions
Multideterminant wave functions
Reduced density matrices of open quantum systems
Single-determinant wave functions
Multideterminant wave functions
An application of the open quantum systems viewpoint: Local spin
Local spin in real space
Local spin from an OQS perspective
Electron number distribution functions
The calculation of EDFs
One-electron functions from real-space domains
Natural adaptive orbitals
Fragment natural orbitals
Natural density partitioning algorithm in real space
Putting the machinery to work
Acknowledgment
References
The Ehrenfest force
Introduction
The stress tensor
Ehrenfest partitioning
Properties computed by the Ehrenfest force
The Ehrenfest potential
Conservative force related to the Ehrenfest force
Summary
Acknowledgments
References
Relativistic QTAIM
Introduction
Relativity, relativistic methods, and relativistic quantum chemistry
Relativistic effects in quantum chemistry
Relativistic methods and proper quantum subsystem
Nonrelativistic quantum proper subsystem
Pseudopotential
Dirac-Coulomb
ZORA
Spin-orbit coupling
General case
Relativistic effects on atoms in molecules
Conclusion
References
Chemical insights from the Source Function reconstruction of scalar fields relevant to chemistry
Introduction
The basic tenets of the SF approach
Specific features and general applications of the ED, ESD and MEP SF reconstructions
The case of the ED
ED SF studies of chemical bonding: General aspects
ED SF studies of chemical bonding: The local source for the ED, its energetic components and its profiles
ED SF studies of chemical bonding: The SF profiles
The ED SF and electron delocalization: General aspects
Further ED SF studies using reference points other than the bcps
ED SF and chemical transferability
ED SF software and computational details
The case of the ESD
The origin of the positive and negative ESD local source contribution LSS
Reference points for the ESD SF studies
Easing the interpretation of the atomic ESD SF contributions to s(r): The magnetic and the relaxation components
ESD SF software and computational details
The case of the MEP SF
Preliminary MEP SF studies: Their motivation and the choice of the reference points
Evaluating meaningful SF contributions to the MEP
MEP SF software and computational details
Partial SF reconstructed densities or potentials
Applications of the ED SF
ED SF studies of the hydrogen bonds
ED SF studies of the metal-metal and metal-ligand interactions in organometallic complexes
ED SF studies of electron delocalization and aromaticity
Applications of the ESD SF
ESD SF study of the water triplet 3B1 state
Applications of the MEP SF
MEP SF study of the effect of substitutional and conformational changes on the σ-hole regions in sin 4,4-bipyridine ...
References
Scalar and vector fields derived from magnetically induced current density
Introduction
Magnetically induced current density
Topology of the current density
The current density tensor
ACID
AACID
Vorticity of J(r) (xJ(r))
TVCD
Magnetically induced Lorentz force density
Other invariants of current density tensors
Other scalar fields related to the current density
Conclusions
References
Gradient bundles
Introduction
Methods for creating gradient bundles
Kinetic energy distributions
Changes in gradient bundle size and shape
Predicting reactivity from reactant state charge density
Effect of electric fields on gradient bundles
Outlook
References
Nonnuclear maxima in the molecular electron density
Introduction
NNA in diatomics
NNAs in molecules and complexes
Bright Wilson justification of the first Hohenberg-Kohn theorem
Conclusion
Acknowledgments
References
Spin polarization of the atomic valence shell in metal complexes
Introduction
Laplacian of electron density
Valence shell
Atomic graph
Atomic spin graphs and catastrophe process
Polarization of the metal valence shell in metal-ligand interaction
Atomic graphs in the excited states
Relationship between the atomic graph and the atomic polarization
Energy polarization within the valence shell
Conclusions
References
A bond bundle case study of Diels-Alder catalysis using oriented electric fields
Introduction-Atomic basins and bond bundles
Background
Gradient bundle decomposition
The condensed charge density and bond bundles
Gradient bundle condensed properties and charge density geometry
Visual qualitative inspection of gradient bundle condensed properties
Quantitative condensed property analysis
Electric field charge density response and catalysis
Computational methods
Results and discussion
Ethylene electric field response
Diels-Alder electric field catalysis
Conclusions
Acknowledgments
References
Applications of the quantum theory of atoms in molecules and the interacting quantum atoms methods to the stu ...
Introduction
Review of the quantum theory of atoms in molecules and the interacting quantum atoms energy partition
Quantum theory of atoms in molecules
Interacting quantum atoms energy partition
The chemical nature of hydrogen bonds as revealed by QTAIM and IQA
Some general results
Nonadditive effects of hydrogen bonding
H-bonds and π systems
Analysis of H-bonds in excited states by means of QTAIM and IQA
Doubly and triply H-bonded systems
Summary
Acknowledgment
References
Recent advances on halogen bonds within the quantum theory of atoms-in-molecules
Introduction
QTAIM basics
Specific QTAIM tools for halogen bonds
General aims
The many faces of interaction energies
The IQA decomposition
IQA decomposition and halogen bond strength
Some QTAIM results about halogen bonds
What drives the bond formation?
Prediction models
Looking at interactions along the bond formation path
Conclusions
Acknowledgments
References
The Non-Covalent Interactions index: From biology to chemical reactivity and solid-state
Introduction
Theoretical background
Ligand-protein interactions
Interplay between inter and intramolecular interactions in reaction mechanisms
NCI applied to experimental electron densities
Concluding remarks
References
Index
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Z