| Acronym | Meaning |
| RSF | Radial Structure Function |
| CME | Coronal Mass Ejection |
| APS | Appearance Potential Spectroscopy |
| SWMM | Stormwater Management Model |
| PNO | Pair Natural Orbital |
| HCI | Highly Charged Ion |
| LT2ESWTR | Long-Term 2 Enhanced Surface Water Treatment Rule [of US EPA] |
| CCSA | Classical Cintrifugal-sudden Approxn. |
| PIMS | Process Information Management System |
| SCBA | Self-consistent Born Approximation |