00. GENERAL

01. Communication, education, history, and philosophy

01.20.+x Communication forms and techniques

01.40.-d Education

01.65.+g History of science

01.70.+w Philosophy of science

02. Mathematical methods in physics

02.10.-v Logic, set theory, and algebra [in Abstract mathematics and Algebra]

02.10.Ox Combinatorics; graph theory

02.10.Ud Linear algebra

02.10.Yn Matrix theory

02.20.-a Group theory

xx.xx.xx Symmetry

02.30.-f Function theory, analysis [in Analysis and Equations]

xx.xx.xx Basic analysis

xx.xx.xx Difference equations

02.30.Gp Special functions

02.30.Hq Ordinary differential equations

02.30.Jr Partial differential equations

02.30.Mv Approximations and expansions

02.30.Rz Integral equations

02.30.Sa Functional analysis

xx.xx.xx Path integrals

xx.xx.xx Renormalization group theory

02.40.-k Geometry, differential geometry, and topology

02.50.-r Probability theory, stochastic processes, and statistics

02.50.Cw Probability theory

02.50.Ey Stochastic processes

xx.xx.xx Markov chains and random walks

xx.xx.xx Random matrix theory

xx.xx.xx Random fields

xx.xx.xx Statistics

02.60.-x Numerical approximation and analysis

02.70.-c Computational techniques

03. Quantum mechanics, field theories, and special relativity

03.50.-z Classical field theories

03.65.-w Quantum mechanics

03.65.Ta Foundations of quantum mechanics; measurement theory

xx.xx.xx Methods

xx.xx.xx Models and concepts

03.65.Yz Decoherence; open systems; quantum statistical methods

04. General relativity and gravitation

05. Statistical physics, thermodynamics, and nonlinear dynamical systems

xx.xx.xx Foundations

xx.xx.xx Methods

05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion

05.50.+q Lattice theory and statistics (Ising, Potts, etc.)

xx.xx.xx Gas models

05.70.-a Thermodynamics

05.70.Fh Phase transitions: general studies

05.70.Ln Nonequilibrium and irreversible thermodynamics

06. Metrology, measurements, and laboratory procedures

10. THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

20. NUCLEAR PHYSICS

30. ATOMIC AND MOLECULAR PHYSICS

40. ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID MECHANICS

41. Electromagnetism; electron and ion optics

42. Optics

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. Physics of plasmas and electric discharges

60. CONDENSED MATTER: STRUCTURAL, MECHANICAL AND THERMAL PROPERTIES

61. Structure of solids and liquids; crystallography

61.20.-p Structure of liquids

61.30.-v Liquid crystals

61.41.+e Polymers, elastomers, and plastics

61.43.-j Disordered solids

61.50.-f Crystalline state

61.72.-y Defects and impurities in crystals; microstructure

62. Mechanical and acoustical properties of condensed matter

63. Lattice dynamics

63.20.-e Phonons in crystal lattices

63.22.+m Phonons or vibrational states in low-dimensional structures and nanoscale materials

63.50.+x Vibrational states in disordered systems

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 low-dimensional systems

68.43.-h Chemisorption/physisorption: adsorbates on surfaces

68.43.De Statistical mechanics of adsorbates

68.65.-k Low-dimensional, mesoscopic, and nanoscale systems: structure and nonelectronic properties

68.65.Ac Multilayers

68.65.Cd Superlattices

68.65.Fg Quantum wells

68.65.Hb Quantum dots

68.65.La Quantum wires

70. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES

71. Electronic structure of bulk materials

71.10.-w Theories and models of many-electron systems

71.15.-m Methods of electronic structure calculations

71.15.Ap Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)

71.15.Dx Computational methodology (Brillouin zone sampling, iterative diagonalization, pseudopotential construction)

71.15.Mb Density functional theory, local density approximation, gradient and other corrections

71.15.Nc Total energy and cohesive energy calculations [Geometry optimization]

71.15.Pd Molecular dynamics calculations (Car-Parrinello) and other numerical simulations

71.15.Qe Excited states: methodology

71.15.Rf Relativistic effects

xx.xx.xx Tight binding

71.20.-b Electron density of states and band structure of crystalline solids

71.23.-k Electronic structure of disordered solids

71.27.+a Strongly correlated electron systems; heavy fermions

71.35.-y Excitons and related phenomena

71.38.-k Polarons and electron-phonon interactions

71.55.-i Impurity and defect levels

72. Electronic transport in condensed matter

73. Electronic structure and electrical properties of surfaces, interfaces, thin films, and low-dimensional structures

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

78.20.-e Optical properties of bulk materials and thin films

78.30.-j Infrared and Raman spectra

78.40.-q Absorption and reflection spectra: visible and ultraviolet

78.55.-m Photoluminescence, properties and materials

78.60.-b Other luminescence and radiative recombination

78.60.Fi Electroluminescence

78.60.Kn Thermoluminescence

78.66.-w Optical properties of specific thin films

78.67.-n Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures

79. Electron and ion emission by liquids and solids; impact phenomena

80. INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

82. Physical chemistry and chemical physics

87. Biological and medical physics

90. GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS

95. Fundamental astronomy and astrophysics; instrumentation, techniques, and astronomical observations

96. Solar System

96.20.-n Moon

96.30.-t Planets, their satellites and rings; asteroids

96.30.Ys Asteroids

96.50.Gn Comets

96.50.Kr Meteors, meteoroids, and meteor streams

96.60.-j Solar physics

97. Stars

97.30.-b Variable and peculiar stars (including novae)

97.80.-d Binary and multiple stars

98. Stellar systems; interstellar medium; galactic and extragalactic objects and systems; the Universe

98.20.-d Stellar clusters and associations

98.35.-a Characteristics and properties of the Milky Way galaxy

98.38.-j Interstellar medium (ISM) and nebulae in Milky Way

98.52.-b Normal galaxies; extragalactic objects and systems (by type)

98.54.-h Quasars; active or peculiar galaxies, objects, and systems

98.56.-p Local group; Magellanic Clouds

98.65.-r Galaxy groups, clusters, and superclusters; large scale structure of the Universe

98.80.-k Cosmology