31. Electronic structure of atoms, molecules and their ions: theory
31.10.+z Theory of electronic structure, electronic transitions, and chemical binding
31.15.-p Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations) (see also 02.70 computational techniques, in mathematical methods in physics)
31.15.Ar Ab initio calculations
31.15.Bs Statistical model calculations (including Thomas-Fermi and Thomas-Fermi-Dirac models)
31.15.Ct Semi-empirical and empirical calculations (differential overlap, Hückel, PPP methods, etc.)
31.15.Dv Coupled cluster theory
31.15.Ew Density-functional theory
31.15.Fx Finite-difference schemes
31.15.Gy Semiclassical methods
31.15.Hz Group theory
31.15.Ja Hyperspherical methods
31.15.Kb Path-integral methods
31.15.Lc Quasiparticle methods
31.15.Md Perturbation theory
31.15.Ne Self-consistent-field methods
31.15.Pf Variational techniques
31.15.Qg Molecular dynamics and other numerical methods
31.15.Rh Valence bond calculations
31.25.-v Electron correlation calculations for atoms and molecules
31.25.Eb Electron correlation calculations for atoms and ions: ground state
31.25.Jf Electron correlation calculations for atoms and ions: excited states
31.25.Nj Electron correlation calculations for diatomic molecules
31.25.Qm Electron correlation calculations for polyatomic molecules
31.30.-i Corrections to electronic structure
31.30.Gs Hyperfine interactions and isotope effects, Jahn-Teller effect
31.30.Jv Relativistic and quantum electrodynamic effects in atoms and molecules
31.50.+w Excited states
31.70.-f Effects of atomic and molecular interactions on electronic structure (see also 34 Atomic and molecular collision processes and interactions)
31.70.Dk Environmental and solvent effects
31.70.Hq Time-dependent phenomena: excitation and relaxation processes, and reaction rates (for chemical kinetics aspects, see 82.20.R)
31.70.Ks Molecular solids
31.90.+s Other topics in the theory of the electronic structure of atoms, molecules, and their ions (restricted to new topics in section 31)
32. Atomic properties and interactions with photons
32.10.-f Properties of atoms and atomic ions
32.10.Bi Atomic masses, mass spectra, abundances, and isotopes (for mass spectroscopy, see 07.75 and 82.80.M)
32.10.Dk Electric and magnetic moments, polarizability
32.10.Fn Fine and hyperfine structure
32.10.Hq Ionization potentials, electron affinities
32.30.-r Atomic spectra
32.30.Bv Radio-frequency, microwave, and infrared spectra
32.30.Dx Magnetic resonance spectra
32.30.Jc Visible and ultraviolet spectra
32.30.Rj X-ray spectra
32.50.+d Fluorescence, phosphorescence (including quenching)
32.60.+i Zeeman and Stark effects
32.70.-n Intensities and shapes of atomic spectral lines
32.70.Cs Oscillator strengths, lifetimes, transition moments
32.70.Fw Absolute and relative intensities
32.70.Jz Line shapes, widths, and shifts
32.80.-t Photon interactions with atoms (see also 42.50 Quantum optics)
32.80.Bx Level crossing and optical pumping
32.80.Cy Atomic scattering, cross sections, and form factors; Compton scattering
32.80.Dz Autoionization
32.80.Fb Photoionization of atoms and ions
32.80.Gc Photodetachment of atomic negative ions
32.80.Hd Auger effect and inner-shell excitation or ionization
32.80.Lg Mechanical effects of light on atoms, molecules, and ions
32.80.Pj Optical cooling of atoms; trapping
32.80.Qk Coherent control of atomic interactions with photons
32.80.Rm Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states)
32.80.Wr Other multiphoton processes
32.80.Ys Weak-interaction effects in atoms
32.90.+a Other topics in atomic properties and interactions of atoms and ionswith photons (restricted to new topics in section 32)
33. Molecular properties and interactions with photons
33.15.-e Properties of molecules and molecular ions
33.15.Bh General molecular conformation and symmetry; stereochemistry
33.15.Dj Interatomic distances and angles
33.15.Fm Bond strengths, dissociation energies
33.15.Hp Barrier heights (internal rotation, inversion, rotational isomerism, conformational dynamics)
33.15.Kr Electric and magnetic moments (and derivatives), polarizability, and magnetic susceptibility
33.15.Mt Rotation, vibration, and vibration-rotation constants
33.15.Pw Fine and hyperfine structure
33.15.Ry Ionization potentials, electron affinities, molecular core binding energy
33.15.Ta Mass spectra
33.15.Vb Correlation times in molecular dynamics
33.20.-t Molecular spectra
33.20.Bx Radio-frequency and microwave spectra
33.20.Ea Infrared spectra
33.20.Fb Raman and Rayleigh spectra (including optical scattering)
33.20.Kf Visible spectra
33.20.Lg Ultraviolet spectra
33.20.Ni Vacuum ultraviolet spectra
33.20.Rm X-ray spectra
33.20.Sn Rotational analysis
33.20.Tp Vibrational analysis
33.20.Vq Vibration-rotation analysis
33.20.Wr Vibronic, rovibronic, and rotation-electron-spin interactions
33.25.+k Nuclear resonance and relaxation (see also 76.60 Nuclear magnetic resonance and relaxation in condensed matter)
33.35.+r Electron resonance and relaxation (see also 76.30 Electron paramagnetic resonance and relaxation in condensed matter)
33.40.+f Multiple resonances (including double and higher-order resonance processes, such as double nuclear magnetic resonance, electron double resonance, and microwave optical double resonance) (see also 76.70 Magnetic double resonances and cross effects in condensed matter)
33.45.+x Mössbauer spectra (see also 76.80 Mössbauer effect; other X-ray spectroscopy)
33.50.-j Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion) (for energy transfer, see also 34)
33.50.Dq Fluorescence and phosphorescence spectra
33.50.Hv Radiationless transitions, quenching
33.55.-b Optical activity and dichroism; magnetooptical and electrooptical spectra
33.55.Ad Optical activity, optical rotation; circular dichroism
33.55.Be Zeeman and Stark effects
33.55.Fi Other magnetooptical and electrooptical effects
33.60.-q Photoelectron spectra
33.60.Cv Ultraviolet and vacuum ultraviolet photoelectron spectra
33.60.Fy X-ray photoelectron spectra
33.70.-w Intensities and shapes of molecular spectral lines and bands
33.70.Ca Oscillator and band strengths, lifetimes, transition moments, and Franck–Condon factors
33.70.Fd Absolute and relative line and band intensities
33.70.Jg Line and band widths, shapes, and shifts
33.80.-b Photon interactions with molecules (see also 42.50 Quantum optics)
33.80.Be Level crossing and optical pumping
33.80.Eh Autoionization, photoionization, and photodetachment
33.80.Gj Diffuse spectra; predissociation, photodissociation
33.80.Ps Optical cooling of molecules; trapping
33.80.Rv Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states)
33.80.Wz Other multiphoton processes
33.90.+h Other topics in molecular properties and interactions with photons (restricted to new topics in section 33)
34. Atomic and molecular collision processes and interactions (for atomic, molecular, and ionic collisions in plasma, see 52.20.H)
34.10.+x General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.)
34.20.-b Interatomic and intermolecular potentials and forces, potential energy surfaces for collisions
34.20.Cf Interatomic potentials and forces
34.20.Gj Intermolecular and atom-molecule potentials and forces
34.20.Mq Potential energy surfaces for collisions (see also 82.20.K Potential energy surfaces for chemical reactions)
34.30.+h Intramolecular energy transfer; intramolecular dynamics; dynamics of van der Waals molecules
34.50.-s Scattering of atoms, molecules, and ions
34.50.Bw Energy loss and stopping power
34.50.Dy Interactions of atoms, molecules, and their ions with surfaces; photon and electron emission; neutralization of ions
34.50.Ez Rotational and vibrational energy transfer
34.50.Fa Electronic excitation and ionization of atoms (including beam-foil excitation and ionization)
34.50.Gb Electronic excitation and ionization of molecules; intermediate molecular states (including lifetimes, state mixing, etc.)
34.50.Lf Chemical reactions, energy disposal, and angular distribution, as studied by atomic and molecular beams (for atomic and molecular beam reactions, see 82.40.D)
34.50.Pi State-to-state scattering analyses
34.50.Rk Laser-modified scattering and reactions
34.60.+z Scattering in highly excited states (e.g., Rydberg states)
34.70.+e Charge transfer (for charge transfer reactions, see 82.30.F)
34.80.-i Electron scattering (for electron collisions in plasma, see 52.20.F)
34.80.Bm Elastic scattering of electrons by atoms and molecules
34.80.Dp Atomic excitation and ionization by electron impact
34.80.Gs Molecular excitation and ionization by electron impact
34.80.Ht Dissociation and dissociative attachment by electron impact
34.80.Kw Electron-ion scattering; excitation and ionization
34.80.Lx Electron-ion recombination and electron attachment
34.80.My Fundamental electron inelastic processes in weakly ionized gases
34.80.Nz Spin dependence of cross sections; polarized electron beam experiments
34.80.Pa Coherence and correlation in electron scattering
34.80.Qb Laser-modified scattering
34.85.+x Positron scattering
34.90.+q Other topics in atomic and molecular collision processes and interactions (restricted to new topics in section 34)
36. Studies of special atoms, molecules, and their ions; clusters
36.10.-k Exotic atoms and molecules (containing mesons, muons, and other unusual particles)
36.10.Dr Positronium, muonium, muonic atoms and molecules
36.10.Gv Mesonic atoms and molecules, hyperonic atoms and molecules
36.20.-r Macromolecules and polymer molecules (for polymer reactions and polymerization, see 82.35; for biological macromolecules and polymers, see 87.15)
36.20.Cw Molecular weights, dispersity
36.20.Ey Conformation (statistics and dynamics)
36.20.Fz Constitution (chains and sequences)
36.20.Hb Configuration (bonds, dimensions)
36.20.Kd Electronic structure and spectra
36.20.Ng Vibrational and rotational structure, infrared and Raman spectra
36.40.-c Atomic and molecular clusters (see also 61.46 Clusters, nanoparticles and nanocrystalline materials)
36.40.Cg Electronic and magnetic properties of clusters
36.40.Ei Phase transitions in clusters
36.40.Gk Plasma and collective effects in clusters
36.40.Jn Reactivity of clusters
36.40.Mr Spectroscopy and geometrical structure of clusters
36.40.Qv Stability and fragmentation of clusters
36.40.Sx Diffusion and dynamics of clusters
36.40.Vz Optical properties of clusters
36.40.Wa Charged clusters
36.90.+f Other special atoms, molecules, ions, and clusters (restricted to new topics in section 36)
39. Instrumentation and techniques for atomic and molecular physics
39.10.+j Atomic and molecular beam sources and techniques
39.20.+q Atom interferometry techniques (see also 03.75.D Atom and neutron interferometry)
39.30.+w Spectroscopic techniques (see also 78.47 Time-resolved optical spectroscopies and other ultrafast optical measurements in condensedmatter)
39.90.+d Other instrumentation and techniques for atomic and molecular physics (restricted to new topics in section 39)