| Acronym | Meaning |
| REELS | Reflection Electron Energy-loss Spectroscopy |
| UCID | Unrestricted CI (with) Single (and) Double (excitations) |
| FO-CPHF | First-order Coupled Perturbed Hartree-Fock Theory |
| LRTI | Lower Respiratory Tract Infection |
| EMA | Effective Medium Approximation |
| AA | Assistant Administrator |
| REOS | Remote Electro-Optical Sensor |
| ACIMS | Active Chemical Ionization Mass Spectroscopy |
| IUMS | International Union Of Microbiological Societies |
| QDA | Quadratic Discriminant Analysis |