This reference book contains information about the structure and properties of atomic and molecular particles, as well as some of the nuclear parameters. It includes data which can be of use when studying atomic and molecular processes in the physics of gases, chemistry of gases and gas optics, in plasma physics and plasma chemistry, in physical chemistry and radiation chemistry, in geophysics, astrophysics, solid-state physics and a variety of cross-discipli nary fields of science and technology. Our aim was to collect carefully selected and estimated numerical values for a wide circle of microscopic parameters in a relatively "not thick" book. These values are of constant use in the work of practical investigators. In essence, the book represents a substantially revised and extended edi tion of our reference book published in Russian in 1980. Two main reasons made it necessary to rework the material. On the one hand, a great deal of new high-quality data has appeared in the past few years and furthermore we have enlisted many sources of information previously inaccessible to us. On the other hand, we have tried to insert extensive information on new, rapidly progressing branches of physical research, such as multiply charged ions, Rydberg atoms, van der Waals and excimer molecules, complex ions, etc. All this brings us to the very edge of studies being carried out in the field.
1. Introduction.- 2. Units of Physical Quantities.- 2.1 Systems of Units in Physics.- 2.2 Fundamental Physical Constants.- 2.3 Systems of Units Based on Natural Standards.- 2.4 Tables of Conversion Factors.- I Atoms and Atomic Ions.- 3. Isotopic Composition, Atomic Mass Table and Atomic Weights of the Elements.- 3.1 Parameters of Stable and Long-Lived Isotopes.- 3.2 Atomic Weights of the Elements and Atomic Mass Table.- 4. Structure of Atomic Electron Shells.- 4.1 Electron Configurations and Ground-State Terms.- 4.2 The Periodic Table.- 4.3 Parameters of Wavefunctions for Valence Electrons in Atoms, Positive and Negative Ions.- 5. Energetics of Neutral Atoms.- 5.1 Ionization Potentials of Atoms.- 5.2 Quantum Defects of Atomic Rydberg States.- 5.3 Fine-Structure Splitting of Atomic Energy Levels.- 5.4 Hyperfine Structure of Atomic Energy Levels.- 5.5 Isotope Shifts of Low-Lying Atomic Levels.- 5.6 Atoms in Static Electric and Magnetic Fields. Atomic Polarizabilities and Magnetic Susceptibilities.- 6. Energetics of Atomic Ions.- 6.1 Ionization Potentials of Atomic Ions.- 6.2 Electron Affinities of Atoms.- 6.3 Energy Levels of Multiply Charged Atomic Ions.- 7. Spectroscopic Characteristics of Neutral Atoms.- 7.1 Low-Lying Atomic Terms.- 7.2 Diagrams of Atomic Energy Levels and Grotrian Diagrams.- 7.3 Atomic Oscillator Strengths in Absorption.- 7.4 Lifetimes of Resonant Excited States in Atoms.- 7.5 Energy Levels and Lifetimes for Metastable States in Atoms.- 7.6 Lifetimes of Atomic Rydberg States.- 8. Spectroscopic Characteristics of Atomic Positive Ions.- 8.1 Low-Lying Terms of Singly Ionized Atoms.- 8.2 Lifetimes of Resonant Excited States in Atomic Ions.- 8.3 Energy Levels and Lifetimes for Metastable States in Singly Ionized Atoms.- 8.4 Optical Parameters of Multiply Charged Atomic Ions.- II Molecules and Molecular Ions.- 9. Interaction Potentials Between Atomic and Molecular Species.- 9.1 Van der Waals Coefficients for Interatomic Multipole Interactions.- 9.2 Long-Range Exchange Interactions of Atoms.- 9.3 Short-Range Repulsive Interactions Between Atomic and Molecular Species.- 10. Diatomic Molecules.- 10.1 Electron Configurations of Diatomic Molecules.- 10.2 Asymptotic Parameters of Wavefunctions for Valence Electrons in Diatomic Molecules.- 10.3 Spectroscopic Constants of Diatomic Molecules.- 10.4 Potential Energy Curves.- 10.5 Ionization Potentials of Diatomic Molecules.- 10.6 Dissociation Energies of Diatomic Molecules.- 10.7 Lifetimes of Excited Electron States in Diatomic Molecules.- 10.8 Parameters of Excimer Molecules.- 10.9 Einstein Coefficients for Spontaneous Emission from Vibrationally Excited Diatomic Molecules.- 11. Diatomic Molecular Ions.- 11.1 Electron Configurations and Asymptotic Parameters of Wavefunctions for Valence Electrons in Diatomic Molecular Ions.- 11.2 Spectroscopic Constants of Diatomic Molecular Ions.- 11.3 Dissociation Energies of Diatomic Molecular Ions.- 11.4 Electron Affinities of Diatomic Molecules.- 11.5 Proton Affinities of Atoms.- 11.6 Lifetimes of Excited Electron States in Diatomic Molecular Ions.- 12. Van der Waals Molecules.- 12.1 Potential Well Parameters of Van der Waals Molecules.- 12.2 Potential Well Parameters of Van der Waals Molecular Ions.- 12.3 Ionization Potentials of Van der Waals Molecules.- 13. Polyatomic Molecules.- 13.1 Constants of Triatomic Molecules.- 13.2 Ionization Potentials of Polyatomic Molecules.- 13.3 Bond Dissociation Energies of Polyatomic Molecules.- 13.4 Lifetimes of Vibrationally Excited Polyatomic Molecules.- 14. Polyatomic Molecular Ions.- 14.1 Bond Dissociation Energies of Complex Positive Ions.- 14.2 Bond Dissociation Energies of Complex Negative Ions.- 14.3 Electron Affinities of Polyatomic Molecules.- 14.4 Proton Affinities of Molecules.- 15. Electrical Properties of Molecules.- 15.1 Dipole Moments of Molecules.- 15.2 Molecular Polarizabilities.- 15.3 Quadrupole Moments of Molecules.- Mathematical Appendices.- A. Coefficients of Fractional Parentage.- B. Clebsch-Gordan Coefficients.