| Acronym | Meaning |
 | PCOP | Positron Correlation Polarization (potential) |
 | HTP | High Temperature And Pressure |
 | FFF | Field-flow Fractionation |
 | UHF-AA | Unrestricted Hartree-Fock (with Spin) Annihilation |
 | HSE | Health And Safety Executive |
 | OGE | One Gluon Exchange |
 | EGCI | Exponentially Generated Configuration Interaction |
 | AAL | Acceptable Ambient Level(s) |
 | IGBP | International Geosphere Biosphere Programme |
 | FEGO | Floating Ellipsoidal Gaussian Orbital |