| Acronym | Meaning |
| MQDT | Multichannel Quantum Defect Theory |
| MRD-CI | Multireference Double-excitation Configuration Interaction |
| RS-LMTO-ASA | Real Space-linear Combination Of Muffin-tin Orbitals-atomic Sphere Approxn. |
| CISC | Configuration Interaction (with) Size-consistency (correction) |
| CROSSBOW | Computerized Retrieval Of Organic Structures Based On Wiswesser |
| NRA | National Rivers Authority (UK) |
| PIES | Pollution Prevention Information Exchange System |
| RESAM | Regional Soil Acidification Model |
| CREST | Center For Renewable Energy And Sustainable Technology |
| PMSR | Pairwise-mixing Stirred Reactor |