1998 PACS - Hierarchical List

   00.       SUMMARY OF PACS SCHEME
01.      Communication, education, history, and philosophy
02.      Mathematical methods in physics
03.      Quantum mechanics, field theories, and special
04.      General relativity and gravitation 
05.      Statistical physics and thermodynamics
06.      Metrology, measurements, and laboratory procedures
07.      Instruments, apparatus, components, and techniques common to 
   10.      THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
11.      General theory of fields and particles
12.      Specific theories and interaction models; particle systematics
13.      Specific reactions and phenomenology
14.      Properties of specific particles 
   20.      NUCLEAR PHYSICS
21.      Nuclear structure
23.      Radioactive decay and in-beam spectroscopy
24.      Nuclear reactions: general
25.      Nuclear reactions: specific reactions
26.      Nuclear Astrophysics 
27.      Properties of specific nuclei listed by mass ranges
28.      Nuclear engineering and nuclear power studies
29.      Experimental methods and instrumentation for elementary-particle
           and nuclear physics
   30.      ATOMIC AND MOLECULAR PHYSICS
31.      Electronic structure of atoms, molecules and their ions: theory
32.      Atomic  properties and interactions with photons
33.      Molecular properties and interactions with photons
34.      Atomic and molecular collision processes and interactions
36.      Studies of special atoms, molecules and their ions; clusters
39.      Instrumentation and Techniques for Atomic and Molecular Physics
   40.      ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL
41.      Electromagnetism; electron and ion optics
42.      Optics
43.      Acoustics
44.      Heat transfer, thermal and thermodynamic processes
45.   Classical mechanics of discrete systems
46.      Continuum mechanics of solids
47.      Fluid dynamics
   50.      PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
51.      Physics of gases
52.      The physics of plasmas and electric discharges
   60.      CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES
61.      Structure of solids and liquids; crystallography
62.      Mechanical and acoustical properties of condensed matter
63.      Lattice dynamics
64.      Equations of state, phase equilibria, and phase transitions
65.      Thermal properties of condensed matter
66.      Transport properties of condensed matter (nonelectronic)
67.      Quantum fluids and solids; liquid and solid helium
68.      Surfaces and interfaces; thin films and whiskers (structure 
and nonelectronic properties) 70. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES 71. Electronic structure 72. Electronic transport in condensed matter 73. Electronic structure and electrical properties of surfaces, interfaces, and thin films 74. Superconductivity 75. Magnetic properties and materials 76. Magnetic resonances and relaxations in condensed matter, Mossbauer effect 77. Dielectrics, piezoelectrics, and ferroelectrics and their properties 78. Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation 79. Electron and ion emission by liquids and solids; impact phenomena 80. INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY 81. Materials science 82. Physical chemistry 83. Rheology 84. Electronics; radiowave and microwave technology; direct energy
conversion and storage 85. Electronic and magnetic devices; microelectronics 87. Biological and medical physics 89. Topics of general interest to physicists 90. GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS 91. Solid Earth physics 92. Hydrospheric and atmospheric geophysics 93. Geophysical observations, instrumentation, and techniques 94. Aeronomy and magnetospheric physics 95. Fundamental astronomy and astrophysics; instrumentation, techniques and astronomical observations 96. Solar System 97. Stars 98. Stellar systems; interstellar medium; galactic and
extragalactic objects and systems; the Universe