| Acronym | Meaning |
| MCE | Mixed Cellulose Ester |
| MCE | Multichannel Eikonal (method For Scattering Calcns.) |
| MCEB | Multiconfiguration Energy Bound |
| MCEB-NEV | Multiconfigurational Energy Bound-natural Eigenvalue Method |
| MCEP | Multiconfigurational Electron Propagator (in Ionization Potential Calcns.) |
| MCF | Monocyte Cytotoxicity Factor |
| MCF | Mutually Consistent Field Method (in Calcns. On Intermolecular Interactions) |
| MCFC | Molten Carbonate Fuel Cells |
| MCGR | Monte-Carlo Renormalization Group |
| MCH | Mean Cell Hemoglobin |
| MCH | Melanin Concentrating Hormone |
| MCHC | Mean Corpuscular Hemoglobin Concentration (occupational Exposure) |
| MCHF | Multiconfiguration Hartree-Fock |
| MCHF-BP | Multiconfiguration Hartree-Fock Breit-Pauli |
| MCI | Mild Cognitive Impairment |
| MCIC | Metals And Ceramics Information Center |
| MCK | Muscle Creatine Kinase |
| MCL | Maximum Contaminant Level |
| MCL | Method Calibration Limit |
| MCLED | Microcavity Light-emitting Diode |
| MCLG | Maximum Contaminant Level Goal |
| MCLR | Multiconfigurational Linear Response (an MC-SCF Method) |
| MCLT | Minority Carrier Lifetime |
| MCM | Mesoporous Crystalline Material |
| MCM | Minichromosome Maintenance |
| MCM | Multichip Modules |
| MCM | Multiconfigurational (variation Of) Moments (for Mo Correlation Diagrams Calcn.) |
| MCM 41 | Mobil Catalytic Material 41 |
| MCMC | Markov Chain Monte Carlo |
| MCMP | Modified Corrugated Morse Potential |
| MCN | Microconcentric Nebulizer |
| MCNDO | Modified Complete Neglect Of Differential Overlap |
| MCNP | General Monte Carlo Code For Neutron And Photon Transport |
| MCOPM | Multiconfiguration Optimized Potential Model |
| MCP | Major Capsid Protein |
| MCP | Microchannel Plate |
| MCP | Model Core Potential |
| MCP | Monocyte Chemoattractant Protein |
| MCP2P | Multiconfigurational Particle-particle Propagator |
| MCPA | 2-methyl-4-chlorophenoxyacetic Acid |
| MCPA | Molecular Coherent-potential Approximation |
| MCPB | (4-(2-methyl-4-chlorophenoxy)butyric Acid |
| MCPF | Modified Coupled-pair Functional (method In CI Calcns.) |
| MCPF+R | Modified Coupled-pair Functional (method With) Relativistic (correction) |
| MCPI | Monte Carlo Path Integration |
| MCPN | Matrix Coherent Potential Approximation |
| MCPP | (+/-)-2-(4-chloro-2-methylphenoxy)propionic Acid (REG: 7085190) |
| MCPSAG | Marcus-Coltrin-Path Semiclassical Adiabatic Ground-state (transmission Coeffs.) |
| MCQDA | Multichannel Quantum Defect Analysis |
| MCQDPT2 | Second-order Multiconfigurational Quasi-degenerate Perturbation |