Ideally a basis set of adequate size is chosen for a particular state of a molecule and the {'s are optimized for each ... Although STFs are more accurate than GTFs for nonlinear polyatomic molecules, they have been used infrequently ...

Author: Robert S. Mulliken

Publisher: Elsevier

ISBN: 9780323149945

Category: Science

Page: 448

View: 777

Polyatomic Molecules: Results of Ab Initio Calculations describes the symmetry of polyatomic molecules in ground states. This book contains 12 chapters that also cover the excited and ionized states of these molecules. The opening chapter describes the nature of the various ab initio computational methods. The subsequent four chapters deal with the three-atom systems, differing with respect to the number of hydrogen atoms in the molecules. These chapters also discuss the reaction surfaces of these systems. These topics are followed by discussions on the molecules whose ground states belong to relatively high, little or no symmetry groups. The concluding chapters explore the inorganic and relatively large organic molecules. These chapters also examine the ab initio calculations of molecular compounds and complexes, as well as hydrogen bonding and ion hydration. This text will be of great value to organic and inorganic chemists and physicists.

With polyatomic molecules we obtain spectral bands which - apart from the overtones - include many different vibrations ( and combinations thereof ) , making the spectrogram too complicated and perplexing . This is inevitable and maybe ...

Author: Theodore Buyana

Publisher: World Scientific

ISBN: 9810208308

Category: Science

Page: 748

View: 822

This book combines in one concise volume the diverse work of several similar books in the market. Each chapter is self-contained and designed to serve the needs of graduates and undergraduates in physics, biochemistry and chemistry. Numerous illustrations accompany the material and more than 60 problems in molecular physics are worked out. Tedious mathematics that obscures the essence of physics is avoided. Though mainly theoretical, many important experimental aspects are included and discussed. It aims at teaching, and not commenting on scientific knowledge. An essential compendium, it can be used both as a textbook and a reference.The main features covered include: Quantum-mechanical treatment of molecular physics; theoretical treatment of molecular spectra and experimental techniques in spectroscopy; interatomic interactions, potentials, molecular stability, energy levels, bonds, rotational and vibrational states, anharmonicity, polarization; theoretical consideration of real molecules. Resonance methods (NMR, NQR, EPR and ENDOR. Theory, experimental apparatus, techniques, numerical results, applications and utility thereof).

CHAPTER I GENERAL TOPICS IN THE THEORY OF THE VIBRATIONAL ABSORPTION SPECTRA OF POLYATOMIC MOLECULES It is quite characteristic that electron movement in the polyatomic molecule is accompanied by a significant periodic alteration of the ...

6 Covalent Bonding IV : Polyatomic Molecules Polyatomic molecules , in this book , are those with more than three atoms . The discussions in this chapter are restricted to a selection of small polyatomic molecules .

Author: Jack Barrett

Publisher: Royal Society of Chemistry

ISBN: 085404647X

Category: Science

Page: 181

View: 829

This book explains in non-mathematical terms where possible, the factors that govern covalent bond formation, the lengths and strengths of bonds and molecular shapes.

There are virtually no H , molecules in the v = 1 level at 20.0 ° C , and even at 1000 ° C there are very few . ... A linear polyatomic molecule has 3N - 5 vibrational modes ( see Section 6.3 ) , where N is the number of atoms .

Author: John Michael Hollas

Publisher: Royal Society of Chemistry

ISBN: 0854046674

Category: Education

Page: 184

View: 833

The latest in the 'Tutorial Chemistry Texts' series, 'Basic Atomic and Molecular Spectroscopy' contains chapters on quantization in polyelectronic atoms, molecular vibrations and electronic spectroscopy.

However , the use of Be values gave re ( C – H ) = 1.06593 Å and re ( C = N ) = 1.15313 Å . 5.8 LINEAR POLYATOMIC MOLECULES The discussion on the spectra of diatomic molecules applies equally well to all linear polyatomic molecules .

Author: D. N. Sathyanarayana

Publisher: New Age International

ISBN: 8122415172

Category: Infrared spectroscopy

Page: 720

View: 450

Vibrational Spectroscopy Provides In A Very Readable Fashion A Comprehensive Account Of The Fundamental Principles Of Infrared And Raman Spectroscopy For Structural Applications To Inorganic, Organic And Coordination Compounds. Theoretical Analyses Of The Spectra By Normal Coordinate Treatment, Factor Group Analysis And Molecular Mechanics Are Delineated.The Book Features: * Coverage From First Principles To Recent Advances * Relatively Self-Contained Chapters * Experimental Aspects * Step By Step Treatment Of Molecular Symmetry And Group Theory * Recent Developments Such As Non-Linear Raman Effects * Comprehensive Treatment Of Rotation Spectroscopy * Band Intensities * Spectra Of Crystals * End-Of-Chapter Exercises.Suitable For Students And Researchers Interested In The Field Of Vibrational Spectroscopy. No Prior Knowledge Of Concepts Specific To Vibrational Spectroscopy Is Necessary. Mathematical Background Such As Matrices And Vectors Are Provided.

Author: Normand M. LaurendeauPublish On: 2005-11-21

Table 9.4 Degrees of freedom for a polyatomic molecule with n atoms Mode Translation Rotation Vibration Linear 3 2 3n - 5 ... Hence , stable molecular configurations for complex molecules must correspond to minima on a multidimensional ...

Author: Normand M. Laurendeau

Publisher: Cambridge University Press

ISBN: 0521846358

Category: Science

Page: 472

View: 862

This 2006 textbook discusses the fundamentals and applications of statistical thermodynamics for beginning graduate students in engineering and the physical sciences.

Author: Vladilen Stepanovich LetokhovPublish On: 2021-07-29

Some 15 years have passed since the first successful experiments were performed on the MP excitation and dissociation of polyatomic molecules with IR laser radiation. Today we have gained not only qualitative, but also quantitative ...

Author: Vladilen Stepanovich Letokhov

Publisher: CRC Press

ISBN: 9781000447859

Category: Science

Page: 396

View: 271

Laser spectroscopy has been perfected over the last fifteen years to become a precise tool for the investigation of highly vibrationally excited molecules. Intense infrared laser radiation permits both the multiple-photon resonant excitation and the dissociation of polyatomic molecules. In this book, the latest results of some of the foremost Soviet researchers are published for the first time in the West. Laser Spectroscopy of Highly Vibrationally Excited Molecules contains a comprehensive study of both the experimental and theoretical aspects of the basic photophysical interactions that occur in these processes. The book first focuses on the nonlinear interaction between the resonant vibrational mode and the intense infrared field and then examines the nonlinear interaction between the vibrational modes themselves due to anharmonicity. These interrelated processes determine all the characteristics of polyatomic molecules in an infrared field. The book also discusses related phenomena such as spectra broadening, optical resonance, photon echoes, and dynamical chaos. It includes examples of multiple-photon resonant excitation such as the excitation of OsO4 by CO^O2 laser radiation, which is detected by the visible luminescence that results. This book will be of great interest to researchers and postgraduate students in infrared laser spectroscopy and the laser chemistry of molecules and applications of isotope separation.

1.5.2 Vibrational Modes of Polyatomic Molecules The atoms in a molecule are always in motion , which may be of different types . The vibrations of a simple diatomic molecule ( A - B ) are the compression or streching along the A - B ...

TE Of great importance in applying statistical methods , particularly to the polyatomic molecules , was a discovery of a combinative diffusion of light by G.S. Landsberg and L.I. Mendelstam in Moscow , and by Raman in Calcutta .