Fine and Hyperfine Structure of Atomic Spectra -- Schrödinger Equation -- Variational Principle For Schrödinger Equation: Orbital Interaction in Hydrogenlike Atoms -- Pauli Equation -- Relativistic Equation for Spin Zero Particle -- Dirac Equation -- Theory of Lamb Shift -- Theory of Spin-1/2 Particles Interacting with Electromagnetic Field -- Particle Motion in Static External Fields -- Origin of Lamb Shift -- Hydrogen Atom.

Atomic Spectroscopy provides a comprehensive discussion on the general approach to the theory of atomic spectra, based on the use of the Lagrangian canonical formalism. This approach is developed and applied to explain the hydrogenic hyperfine structure associated with the nucleus motion, its finite mass, and spin. The non-relativistic or relativistic, spin or spin-free particle approximations can be used as a starting point of general approach. The special attention is paid to the theory of Lamb shift formation. The formulae for hydrogenic spectrum including the account of Lamb shift are written in simple analytical form. The book is of interest to specialists, graduate and postgraduate students, who are involved into the experimental and theoretical research in the field of modern atomic spectroscopy.