| Acronym | Meaning |
| ANO | Average Natural Orbitals |
| RPMI | Roswell Park Memorial Institute |
| SSW | Solid-state Welding |
| DR-RWA | Dominant Resonance-rotating Wave Approximation |
| DI | Direct Injection (engine; Diesel) |
| ACAR | Angular Correlation Of Annihilation Radiation |
| LET | Linear Energy Transfer (in Spacecraft Power Systems) |
| INDO/SP | Intermediate Neglect Of Differential Overlap/spin Polarization |
| SMB | Simulated Moving Bed |
| RTCVD | Rapid Thermal Chem. Vapor Deposition |