AO | Atomic orbital |

CASSCF | Complete active space SCF |

CCSD | Coupled cluster wtih single and double excitations |

CCSDTQ | Coupled cluster wtih single, double, triple, and quadruple excitations |

CI | Configuration interaction |

CIS | Configuration interaction with single excitations |

DFT | Density functional theory |

EAM | Embedded atom model |

ECP | Effective core potential |

EOM | Equation of motion |

FMM | Fast multipole method |

GTO | Gaussian type orbital |

GVB | Generalized valence bond |

GWA | GW approximation |

HDFT | Hybrid density functional theory |

LDA | Local density approximation |

MBPT | Many-body perturbation theory |

MCSCF | Multi-configurational self-consistent field |

MO | Molecular orbital |

MP2, MP3 .. | Moller–Plesset perturbation theory of second, third ... order |

NPH | Constant pressure, constant enthalpy ensemble |

NPT | Constant temperature, constant pressure ensemble (N=# of particles) |

NST | Constant temperature, constant stress ensemble |

NVE | Constant energy, constant volume ensemble |

NVT | Constant temperature, constant volume ensemble |

ONIOM | Our own n-layered integrated molecular orbital and molecular mechanics |

PME | Particle Mesh Ewald |

PPPM | Particle-Particle Particle-Mesh |

QMC | Quantum Monte Carlo |

PSPW | Pseudopotential plane wave |

RHF | Restricted Hartree-Fock |

ROHF | Restricted open-shell Hartree-Fock |

SCF | Self-consistent field |

STO | Slater-type orbital |

TD | Time dependent |

UHF | Unrestricted Hartree-Fock |