| Acronym | Meaning |
| RC(XI) | (fully) Correlated Relativistic Local-density |
| CFO | Crystal Field Orbital |
| MSP | Manganese Stabilizing Protein |
| OAQPSTTN | Office Of Air Quality Planning And Standards Technology Transfer Network |
| IMF | Intermediate Mass Fragment |
| TPY | Total Photon Yield |
| ARP | Adiabatic Rapid Passage |
| ZRL | Zero Risk Level |
| MDHS | Methods For The Determination Of Hazardous Substances |
| PTSA | Pressure And Temperature Swing Adsorption |