MOPAC (Molecular Orbital PACkage) is a semiempirical quantum chemistry program for studying molecules, solids and chemical reactions. It uses simplified quantum-mechanical models whose parameters are fitted to experimental or high-level theoretical data, trading some predictive accuracy for substantially lower computational cost.
The program is primarily command-line driven and uses text input and output files, making it straightforward to incorporate into scripted computational workflows. Its semiempirical approach is particularly useful when conventional ab initio calculations would be too expensive, including screening larger collections of structures and preparing systems for more demanding calculations.
This is free and open source software.
Key Features
- Supports semiempirical Hamiltonians including MNDO, AM1, PM3, RM1, PM6 and PM7.
- Performs molecular and solid-state electronic-structure calculations.
- Optimises molecular geometries and can locate transition states and follow reaction paths.
- Calculates heats of formation, molecular orbitals, gradients and force constants.
- Provides vibrational frequency calculations and thermodynamic analysis.
- Supports closed-shell and open-shell calculations, radicals, ions and polymers.
- Includes COSMO implicit-solvent calculations.
- Calculates polarizabilities and hyperpolarizabilities.
- Accepts Cartesian coordinates, internal coordinates, mixed coordinates and several chemistry-oriented geometry formats.
- Can apply geometry constraints and freeze selected coordinates during optimisation.
- Provides molecular dynamics capabilities for following the time evolution of a system.
- Offers an application programming interface for integrating selected functionality into other software.
- Provides QM/MM facilities for combining quantum-mechanical calculations with an external molecular-mechanics environment.
- Can generate electrostatic-potential and graphics-oriented output for use with molecular visualisation and analysis tools.
Website: github.com/openmopac/mopac
Support:
Developer: Molecular Sciences Software Institute (MolSSI)
License: Apache License 2.0
MOPAC is written in Fortran. Learn Fortran with our recommended free books and free tutorials.
Related Software
| Chemistry Tools | |
|---|---|
| GROMACS | Versatile package to perform molecular dynamics |
| tomviz | Process, visualize, and analyze 3D tomographic data |
| Psi4 | Ab initio quantum chemistry software |
| NWChem | Ab initio computational chemistry software package |
| PyMOL | OpenGL molecular graphics system written in Python |
| LAMMPS | Classical molecular dynamics simulator |
| CP2K | Atomistic simulations of solid state, liquid, molecular and biological systems |
| RDKit | Cheminformatics and machine-learning software |
| GAMESS | General ab initio quantum chemistry package |
| Avogadro | Advanced molecular editor |
| OpenMM | High-performance toolkit for molecular simulation |
| Gabedit | Graphical user interface to computational chemistry packages |
| Open Babel | Converts and manipulates chemical data files |
| Jmol | Viewer for three-dimensional chemical structures |
| pyscf | Quantum chemistry framework |
| Kalzium | Full-featured chemistry application for KDE 5 |
| Ketcher | Web-based chemical structure editor |
| XDrawChem | 2D editor for chemical structures and reactions |
| Cantera | Chemical kinetics, thermodynamics, and transport tool suite |
| Orac | OpenMP/MPI molecular dynamics engine to simulate solvated biomolecules |
| JChemPaint | Chemical 2D structure editor |
| MPQC | Computes the properties of molecules, ab initio |
| Indigo | Universal cheminformatics toolkit for working with molecules and reactions |
| GPAW | Python package for density-functional theory calculations |
| DFTB+ | General package for performing fast atomistic calculations |
| BKChem | 2D molecule editor written in Python |
| MDynaMix | General purpose molecular dynamics |
| ChemCanvas | 2D chemical drawing tool |
| MoleQueue | Abstract, manage, and coordinate the execution of tasks |
Read our verdict in the software roundup.
 Explore our carefully curated directory of recommended free and open source software, covering every major software category.The directory forms part of our extensive collection of articles for Linux enthusiasts. It includes hundreds of detailed reviews, together with free and open source alternatives to proprietary software from companies such as Google, Microsoft, Apple, Adobe, IBM, Cisco, Oracle, and Autodesk. LinuxLinks also covers interesting projects worth exploring, Linux-compatible hardware, free programming books and tutorials, and much more. Know a useful free and open source Linux application that we haven’t covered? Tell us about it using our submission form. |
Please read our Comment Policy before commenting.