Discovering Chemistry With Natural Bond Orbitals

Learn how to investigate chemical bonding questions usingmodern NBO computational methods

Using the latest computational technology, this practical how–toguide to chemical discovery introduces readers to natural bondorbital (NBO) concepts, strategies, and practical implementations.Without resorting to complex mathematics and programming, readerswill learn how to fully leverage the NBO 5.9 computer program tore–express complex multi–electron wave functions in terms ofintuitive chemical concepts and orbital imagery.

Discovering Chemistry with Natural Bond Orbitals begins with anintroductory chapter that sets forth the basics, including how toproduce orbital imagery. Next, the authors cover such criticaltopics as:

Each chapter ends with problems and exercises that enablereaders to apply NBO methods to investigate chemical bonds, theirintrinsic energies, and the corresponding dissociation energiesthat are relevant in reactivity problems. There are also worked–outexamples and sample input and output throughout the text to helpguide and support readers in their own investigations. In addition,the text features numerous sidebars and links to websites and othertexts where more in–depth information can be found on individualtopics.

There are five appendices at the end of the text filled withuseful supplementary material, including Appendix D, "What ifSomething Goes Wrong?", to help readers solve common problems thatarise in NBO investigations.

Following this text′s clear explanations, even readers withlimited backgrounds in quantum mechanics will learn how to performsophisticated explorations of modern bonding and valencyconcepts.

1 Getting Started

1.1 Talking to your electronic structure system

1.2 Helpful tools

1.3 General $NBO keylist usage

1.4 Producing orbital imagery

Problems and Exercises

2 Electrons in Atoms

2.1 Finding the electrons in atomic wavefunctions

2.2 Atomic orbitals and their graphical representation

2.3 Atomic electron configurations

2.4 How to find electronic orbitals and configurations in NBOoutput

2.5 Natural Atomic Orbitals and the Natural Minimal Basis

Problems and Exercises

3 Atoms in Molecules

3.1 Atomic orbitals in molecules

3.2 Atomic configurations and atomic charges in molecules

3.3 Atoms in open–shell molecules

Problems and Exercises

4 Hybrids and Bonds in Molecules

4.1 Bonds and lone pairs in molecules

4.2 Atomic hybrids and bonding geometry

4.3 Bond polarity, electronegativity, and Bent′s rule

4.4 Electron–deficient 3–center bonds

4.5 Open–shell Lewis structures

4.6 Lewis–like structures in transition metal bonding

Problems and Exercises

5 Resonance Delocalization Corrections

5.1 The Natural Lewis Structure perturbative model

5.2 2nd–order perturbative analysis of donor–acceptorinteractions

5.3 $DEL energetic analysis

5.4 Delocalization tails of Natural Localized MolecularOrbitals

5.5 How to $CHOOSE alternative Lewis structures

5.6 Natural Resonance Theory

Problems and Exercises

6 Steric and Electrostatic Effects

6.1 Nature and evaluation of steric interactions

6.2 Electrostatic and dipolar analysis

Problems and Exercises

7 Nuclear and Electronic Spin Effects

7.1 NMR chemical shielding analysis

7.2 NMR J–coupling analysis

7.3 ESR spin–density distribution

Problems and Exercises

8 Coordination and Hyperbonding

8.1 Lewis acid–base complexes

8.2 Transition metal coordinate bonding

8.3 Three–center, four–electron hyperbonding

Problems and Exercises

9 Intermolecular Interactions

9.1 Hydrogen–bonded complexes

9.2 Other donor–acceptor complexes

9.3 Natural energy decomposition analysis

Problems and Exercises

10 Transition State Species and Chemical Reactions

10.1 Ambivalent Lewis structures: the transition–state limit

10.2 Example: bimolecular formation of formaldehyde

10.3 Example: unimolecular isomerization of formaldehyde

10.4 Example: SN2 halide exchange reaction

Problems and Exercises

11 Excited State Chemistry

11.1 Getting to the root of the problem

11.2 Illustrative applications to NO excitations

11.3 Finding common ground: state–to–state NBOtransferability

11.4 NBO/NRT description of excited state structure andreactivity

11.5 Conical intersections and intersystem crossings

Problems and Exercises

Appendix A: What′s Under the Hood?

Appendix B: Orbital Graphics: The NBOView OrbitalPlotter

Appendix C: Digging at the Details

Appendix D: What if Something Goes Wrong?

Appendix E: Atomic Units and Conversion Factors

FRANK WEINHOLD, PhD, is Emeritus Professor of Physicaland Theoretical Chemistry at the University ofWisconsin Madison. Professor Weinhold has served on theeditorial advisory boards of the International Journal of QuantumChemistry and Russian Journal of Physical Chemistry. He is theauthor of more than 170 technical publications and softwarepackages, including the natural bond orbital program.

CLARK R. LANDIS, PhD, is Professor of Inorganic Chemistryat the University of Wisconsin Madison. He has receivedteaching and lectureship awards for his contributions to chemicaleducation. Dr. Landis′s research focuses on catalysis in transitionmetal complexes.

Following this text s clear explanations, evenreaders with limited backgrounds in quantum mechanics will learnhow to perform sophisticated explorations of modern bonding andvalency concepts.   (Chimie Nouvelle, 1 March2013)