## 00. GENERAL

01.20.+x Communication forms and techniques

01.40.-d Education

01.65.+g History of science

01.70.+w Philosophy of science

02.10.Ox Combinatorics; graph theory

02.10.Ud Linear algebra

02.10.Yn Matrix 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

02.50.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

### 03. Quantum mechanics, field theories, and special relativity

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

xx.xx.xx Methods

xx.xx.xx Gas models

05.70.Fh Phase transitions: general studies

05.70.Ln Nonequilibrium and irreversible thermodynamics

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

## 50. PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

### 61. Structure of solids and liquids; crystallography

#### 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

### 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

#### 71.55.-i Impurity and defect levels

### 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

#### 78.20.-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

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

#### 96.20.-n Moon

96.30.Ys Asteroids

96.50.Gn Comets

96.50.Kr Meteors, meteoroids, and meteor streams

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