| Acronym | Meaning |
| APNO | Atomic Pair Natural Orbital |
| MSAE | Multistate Atomic Expansion (method For At. Collisions) |
| UCMR | Unregulated Contaminant Monitoring Regulation |
| NTCF | National Toxics Campaign Fund |
| SPCC | System Performance Check Compound |
| LCCM | Linearized Coupled Cluster Method |
| LWR | Light-water Reactor |
| IMPPT | Intermolecular Moeller-Plesset Perturbation Theory |
| RFQ | Radio-frequency Quadrupole |
| ACM | Aanderaa Current Meter |