| Acronym | Meaning |
| HFG | Hartree-Fock-Gopinathan (quantum Theory Or Wave Function) |
| REACCS | Reaction Access System |
| FOE | First-order Exchange (in Electron-atom Scattering Calcn.) |
| CSF | Configuration Spin Function (a Wave Function) |
| HDEHP | Bis(2-ethylhexyl)phosphoric Acid |
| GM | Geometric Mean |
| ABS | Arc Bond Sputter |
| PSID | Photon Stimulated Ion Desorption |
| FIAS | Flow Injection Atomic Spectrometry |
| RLS | Recursive Least Squares (algorithm) |