Atoms and Molecules in Strong External Fields

This book contains contributions to the 172. WE-Heraeus-Seminar “Atoms and Molecules in Strong External Fields,” which took place April 7–11 1997 at the Phys- zentrum Bad Honnef (Germany). The designation “strong fields” applies to external static magnetic, and/or electric fields that are sufficiently intense to cause alterations in the atomic or molecular str- ture and dynamics. The specific topics treated are the behavior and properties of atoms in strong static fields, the fundamental aspects and electronic structure of molecules in strong magnetic fields, the dynamics and aspects of chaos in highly excited R- berg atoms in external fields, matter in the atmosphere of astrophysical objects (white dwarfs, neutron stars), and quantum nanostructures in strong magnetic fields. It is obvious that the elaboration of the corresponding properties in these regimes causes the greatest difficulties, and is incomplete even today. Present-day technology has made it possible for many research groups to study the behavior of matter in strong external fields, both experimentally and theore- cally, where the phrase “experimentally” includes the astronomical observations. - derstanding these systems requires the development of modern theories and powerful computational techniques. Interdisciplinary collaborations will be helpful and useful in developing more efficient methods to understand these important systems. Hence the idea was to bring together people from different fields like atomic and molecular physics, theoretical chemistry, astrophysics and all those colleagues interested in aspects of few-body systems in external fields.

Table of Contents:
White Dwarfs for Physicists.- Magnetic White Dwarfs: Observations in Cosmic Laboratories.- Hydrogen in Strong Electric and Magnetic Fields and its Application to Magnetic White Dwarfs.- Helium Data for Strong Magnetic Fields Obtained by Finite Element Calculations.- The Spectrum of Atomic Hydrogen in Magnetic and Electric Fields of White Dwarf Stars.- Neutron Star Atmospheres.- Hydrogen Atoms in Neutron Star Atmospheres: Analytical Approximations for Binding Energies.- Absorption of Normal Modes in a Strongly Magnetized Hydrogen Gas.- Electronic Structure of Light Elements in Strong Magnetic Fields.- From Field-Free Atoms to Finite Molecular Chains in Very Strong Magnetic Fields.- The National High Magnetic Field Laboratory — A Precis.- Self-Adaptive Finite Element Techniques for Stable Bound Matter-Antimatter Systems in Crossed Electric and Magnetic Fields.- A Computational Method for Quantum Dynamics of a Three-Dimensional Atom in Strong Fields.- Discretization Techniques Applied to Atoms Under Extreme Conditions.- Computer—Algebraic Derivation of Atomic Feynman—Goldstone Expansions.- Scaled-Energy Spectroscopy of Helium and Barium Rydberg Atoms in External Fields.- Atoms in Crossed Fields.- Hydrogen-Like Ions Moving in a Strong Magnetic Field.- Center-of-Mass Effects on Atoms in Magnetic Fields.- Scaling Properties for Atoms in External Fields.- Time Independent and Time Dependent States of Atoms in Static External Fields.- Secular Motion of 3-D Rydberg States in A Microwave Field.- Spontaneous Decay of Nondispersive Wave Packets.- Ionization of Helium by Static Electric Fields and Short Pulses.- Adiabatic Invariants of Rydberg Electrons in Crossed Fields.- Highly Excited Charged Two-Body Systems in a Magnetic Field: A Perturbation Theoretical Approach to theClassical Dynamics.- Analysis of Quantum Spectra by Harmonic Inversion.- Atoms in External Fields: Ghost Orbits, Catastrophes, and Uniform Semiclassical Approximations.- Quadratic Zeeman Splitting of Highly Excited Relativistic Atomic Hydrogen.- Neutral Two-Body Systems of Charged Particles in External Fields.- Semiclassical Theory of Multielectron Atoms and the H2+ Molecular Ion in Intense External Field.- On the Ground State of the Hydrogen Molecule in a Strong Magnetic Field.- Hydrogen Molecule in Magnetic Fields: On Excited ? States of the Parallel Configuration.- Electronic Properties of Molecules in High Magnetic Fields: Hypermagnetizabilities of H2.- Shallow Donor States in a Magnetic Field.- Quantum Dots in Strong Magnetic Fields.- Density Functional Theory of Quantum Dots in A Magnetic Field.- An Analytical Approach to the Problem of an Impurity Electron in a Quantum Well in the Presence of Electric and Strong Magnetic Fields.