| Acronym | Meaning |
| SAC-CI | Symmetry-adapted Cluster Configuration Interaction (theory For Wave-function Expansion) |
| NGWA | National Ground Water Association |
| ECAO | Environmental Criteria And Assessment Office |
| IHF | Integration Host Factor |
| NICI | Negative Ion Chemical Ionization (mass Spectrometry) |
| TRC | Total Residual Chlorine |
| MCR | Max. Continuous Rating |
| GPS | Global Positioning System |
| SPF | Simons-Parr-Finlan (potential Function) |
| GSCRF | Generalized Self-consistent Reaction Field |