| Acronym | Meaning |
| A/PI | Ab Initio Perturbed Ion (quantum Clacn. Method) |
| PNH | Paroxysmal Nocturnal Hemoglobinuria |
| EO | Ethylene Oxide |
| INA | Ion Neutral Analysis |
| NPIRS | National Pesticide Information Retrieval System |
| EGR | Exhaust Gas Recirculation |
| TCDFT | Two-component Density Functional Theory |
| ACNFS | Advisory Committee On Nuclear Facility Safety |
| CAP | Corrective Action Plan |
| RASSI | Restricted Active Space State Interaction |