| Acronym | Meaning |
| CIOS | Classical Infinite Order Sudden (in Atom-mol. Reaction Calcns.) |
| ASSP | Aerosol Scattering Spectrometer Probe |
| MIESR | Matrix Isolation Electron Spin Resonance |
| HRC | Rockwell Hardness (C Scale) |
| PSSCF | Pseudo SCF |
| NTIAC | Nondestructive Testing Information Analysis Center |
| IEEM | Ion-electron Emission Microscopy |
| SIC-GX-LSD | Self-interaction Corrected Generalized Exchange Local Spin Density |
| FES | Field Emission Spectroscopy |
| BTGA | Best Technology Generally Available |