| Acronym | Meaning |
| MCSX | Multiconfiguration Single Excitation |
| OSW | Office Of Solid Waste (US EPA) |
| IIRF | Infinite Impulse Response Filter |
| RXTE | Rossi X-ray Timing Explorer |
| RSRG | Real-space Renormalization Group (method In Calcn. Of Green Functions For Electrons In Crystals) |
| DIB | Dibutyl Chlorendate |
| DQ-MBPT | Double And Quadruple Excitation Diagrams In Many-body Perturbation Theory |
| QSSA | Quasi-steady-state Approximation |
| DTR | Diffusion Transfer Reversal |
| ROFA | Rotating Over Fire Air (boiler Firing) |