| AM1 | Austin Model 1 |
| CI | Configuration Interaction |
| CRF | Core/Core Repulsion Function |
| CSR | Configuration of Spin Function |
| EF | Eigenvector Following |
| ESP | Electrostatic Potential |
| GUI | Graphical User Interface |
| HE | Half Electron |
| HF | Hartree-Fock |
| HOMO | Highest Occupied Molecular Orbital |
| IP | Ionization Potential |
| IR | Infra-red |
| IRC | Intrinsic Reaction Coordinate |
| LUMO | Lowest Occupied Molecular Orbital |
| MBSP | Molecular Basis Set for Parameterization |
| ME | Multipole Expansion |
| MERP, MEP | Minimum Energy Reaction Pathway |
| MINDO3 | Modified Intermediate Neglect of Differential Overlap, V. 3 |
| MNDO | Modified Neglect of Differential Overlaps Method |
| MNDO/d | Modified Neglect of Differential Overlaps (MNDO) Method with d-orbitals |
| MD | Molecular Dynamics |
| MM | Molecular Mechanics |
| MO | Molecular Orbital |
| NDDO | Neglect of Diatomic Differential Overlap |
| NEV | Negative Eigenvalues |
| PES | Potential Energy Surface |
| PM3 | Parameterization Model 3 |
| RHF | Restricted Hartree-Fock |
| SAM1 | Semi-ab initio Method Version 1 |
| SAM1D | Semi-ab initio Method Version 1 (SAM1) with d-orbitals |
| SCF | Self Consistent Field |
| SMx | Solvation Model x |
| TERI | Two Electron Repulsion Integral |
| TS | Transition State |
| TV | Transition Vector |
| UHF | Unrestricted Hartree-Fock |
| ZPE | Zero Point Energy |