| Acronym | Meaning |
| GQDPT | Generalized Quasidegenerate Perturbation Theory |
| VPAM | Variable Phase Amplitude Method (for Electron-atom Scattering) |
| LOQ | Limit Of Quantitation |
| NIESST | Nuclear Decay-induced Excited-spin-state Trapping |
| IMT | Ion Microtomography |
| UIHRS | Upflow Inclined High-rate Settlers |
| OPPT | Office Of Pollution Prevention And Toxics (US EPA) |
| MET | Many Electron Theory (for Singlet Ground State) |
| AO | Atomic Orbital |
| COH | Coefficient Of Haze |