MOLPRO

MOLPRO
Name	MOLPRO
Developer	Richard J. Harrison; Adrian D. Amos; P. J. Knowles; Hans-Joachim Werner; Peter J. Knowles
Released	1970s
Operating system	Linux; Microsoft Windows; macOS
Programming language	Fortran; C++
Genre	Quantum chemistry software
License	Proprietary

MOLPRO is a comprehensive suite of ab initio quantum chemistry programs focused on high-accuracy electronic structure calculations for molecules and clusters. It provides implementations of correlated wavefunction methods and related techniques used in computational studies by researchers at institutions such as University of Cambridge, Max Planck Society, Imperial College London, and ETH Zurich. The package is widely cited in literature alongside other major packages like Gaussian (software), NWChem, ORCA (chemistry) and CFOUR.

History

Development began in the 1970s within research groups connected to University of Cambridge and collaborators across United Kingdom and Germany. Early authors included figures such as Peter J. Knowles and Hans-Joachim Werner, who established core algorithms for configuration interaction and multiconfigurational self-consistent field methods used in later molecular electronic structure theory. Over successive decades the codebase expanded through contributions from researchers affiliated with Max Planck Institute for Quantum Optics, Fritz Haber Institute, University of Oxford, and industrial laboratories. The project evolved alongside landmark developments in computational chemistry, appearing in discussions with works by John Pople and Walter Kohn and standards set by conferences including Gordon Research Conference, Pacifichem, and meetings of the Royal Society. Historical growth tracked advances in parallel computing at centers such as Argonne National Laboratory and collaborations with initiatives at European Molecular Biology Laboratory.

Features and Capabilities

MOLPRO offers high-accuracy methods tailored for spectroscopic and thermochemical predictions used by groups at National Institutes of Health and European Space Agency. Capabilities include energy gradients, analytic Hessians, and properties calculations exploited in studies published by teams at California Institute of Technology and Massachusetts Institute of Technology. The package supports basis sets from repositories associated with Weizmann Institute of Science and basis set families often cited with the work of Frank Jensen and T. H. Dunning. It interoperates with visualization tools developed at University of California, Berkeley and file formats used in projects from Brookhaven National Laboratory.

Methodologies and Implementations

The suite implements a broad range of wavefunction approaches central to modern computational chemistry debates led by researchers like Anna Krylov and Martin Head-Gordon. Core methods include Hartree–Fock, multiconfigurational self-consistent field (MCSCF), complete active space self-consistent field (CASSCF), multireference configuration interaction (MRCI), coupled-cluster (CCSD, CCSD(T)), and explicitly correlated R12/F12 techniques developed in the tradition of work by Jérôme Chemineau and Klaus R. Sherrill. Advanced implementation details address size-extensivity and basis set convergence issues discussed in the literature from American Chemical Society meetings. Relativistic corrections and pseudopotential treatments align with approaches used at Lawrence Berkeley National Laboratory and researchers such as P. Schwerdtfeger.

Software Architecture and Performance

The codebase is primarily written in Fortran with performance-critical modules in C++, reflecting patterns similar to packages developed at Sandia National Laboratories. Parallelization strategies exploit MPI implementations common at Oak Ridge National Laboratory and use threaded BLAS and LAPACK libraries standardized by communities around Netlib. Performance benchmarks presented in publications compare favorably with results from European Centre for Medium-Range Weather Forecasts compute clusters and high-performance computing centers like PRACE and XSEDE. Memory management, integral evaluation, and disk I/O are optimized for large active spaces in multireference calculations, drawing on algorithmic work from teams at Rutherford Appleton Laboratory.

Licensing and Distribution

Distribution follows a proprietary licensing model favored by academic groups that collaborate with industrial partners such as Shell plc and BASF. Academic and commercial licenses vary, with site licenses and academic discounts similar to arrangements used by Schrödinger (company). Installation packages and compiled binaries are provided for major platforms including Linux distributions used at CERN computing facilities and workstation environments at Harvard University.

Applications and Use Cases

MOLPRO is applied in high-accuracy studies of reaction mechanisms, spectroscopic constants, and potential energy surfaces by research groups at Stanford University, University of Toronto, and University of California, Santa Barbara. Use cases include benchmarking thermochemical datasets connected to projects at National Institute of Standards and Technology, modeling excited states in photochemistry studied at University of Geneva, and calculating van der Waals interactions relevant to work at Max Planck Institute for Polymer Research. It supports investigations into catalysis linked with research at ETH Zurich and heavy-element chemistry cited in publications from Oak Ridge National Laboratory.

Development and Community

Active development is maintained by an international community of authors and contributors affiliated with institutions such as University of Bristol, University of Liverpool, University of Groningen, and research centers including Jülich Research Centre. Users participate through workshops at venues like Gordon Research Conference and training schools sponsored by European Chemistry Thematic Network. The community exchanges benchmarks and implementations in forums similar to those hosted by American Institute of Physics and collaborates on method validation with authors of other packages including Molcas and Psi4.

Category:Computational chemistry software