| Acronym | Meaning |
| QED | Quantum Electrodynamics |
| QEEC | Quasimol. Extended Elementary Cell (for Electronic Structure Calcns. Of Crystals) |
| QEL | Quantity Exclusion Limit |
| QELS | Quasi-Elastic Light Scattering |
| QENS | Quasielastic Neutron Scattering |
| QET | Quasi-equilibrium Theory |
| QFAA | Quartz Furnace Atomic Absorption |
| QFAAS | Quartz Furnace Atomic Absorption Spectrometry |
| QFD | Quantum Fluid Dynamics |
| QFDFT | Quantum-fluid Density-functional Theory |
| QFEB | Quasi-free Electron Bremsstrahlung |
| QFEP | Quantum Free Energy Perturbation (calcn. Method) |
| QFT | Quantum Field Theory |
| QGLE | Quantum Generalized Langevin Equation |
| QGP | Quark Gluon Plasma |
| QHA | Quasi-harmonic Approxn. (in Intramol. Vibrational Relaxation) |
| QHD | Quantum Hadrodynamics |
| QHE | Quantum Hall Effect |
| QIOS | Quantum Infinite-order Sudden (method For Collisions) |
| QIP | Quality Improvement Program |
| QIP | Quantum Information Processing |
| QISM | Quantum Inverse Scattering Method |
| QIT | Quadrupole Ion Trap |
| QITMS | Quadrupole Ion Trap Mass Spectrometry |
| QKM | Quadratic Kohn Method (variational Method For Scattering) |
| QLAR | Quantitative Localization Activity Relationship |
| QLCPMET | Quasilinearized Coupled-pair-many-electron Theory |
| QLDA | Quasilocal Density Functional Approxn. |
| QLGM | Quantum Lattice Gas Model (in Helium Superfluid Transition Temperature In Zeolite Pores) |
| QLSM | Quadratic Least-squares Method (variational For Scattering) |
| QLUC | Quasimolecular Large Unit Cell (model For Electronic-structure Calcns. On Solids) |
| QMAR | Quantitative Migration-activity Relationship |
| QMB | Quartz Microbalance |
| QMC | Quantum Monte-Carlo (theory For Many-electron Atoms And Mols.) |
| QMCRG | Quantum Monte-Carlo Renormalization Group (for Quantum Phase Transitions) |
| QMD | Quantum Molecular Dynamics (for Calcns. On The Dynamics Of A Quantum Particle Coupled To A Classical Many-body System) |
| QMMM | Quantum Mechanics-molecular Mechanics ~ |
| QMO | Quaternionic Molecular Orbital Method |
| QMOM | Quadrature Method Of Moments |
| QMRE | Quantum Mechanical Resonance Energy |
| QMS | Quadrupole Mass Spectrometry |
| QPA | Quantitative Phase Analysis |
| QPCR | Quantitative Polymerase Chain Reaction |
| QPD | Quadrature Phase Detection |
| QPEN | Quantum-mech. Potential (based On Interactios Of) Electrons (and) Nuclei |
| QPF | Quantitative Precipitation Forecasts |
| QPLDA | Quasiparticle Local-density Approxn. |
| QPM | Quantum Poincare Map |
| QPM | Quantum Proximity Microscopy |
| QPM | Quasiparticle Phonon Model |