SCINE Sparrow

Philosophy of SCINE Sparrow

The availability of fast electronic energies and gradients is essential for the SCINE project. The SCINE Sparrow module contains electronic structure models which were designed to yield electronic energies and energy gradients with respect to the nuclear coordinates rapidly. The SCINE Sparrow module can be driven from SCINE Interactive, SCINE Readuct, and SCINE Chemoton. However, as with all SCINE modules it is also a stand-alone program which can be applied on its own or be easily interfaced to other programs.

Technical Details

SCINE Sparrow is a command-line tool that implements many popular semiempirical models. SCINE Sparrow contains methods which require a self-consistent solution of a Roothaan-Hall-type equation (semiempirical methods based on the neglect of diatomic differential overlap approximation and SCC-DFTB) and a non-self-consistent methods (non-SCC DFTB). The application of semiempirical models usually allows for rapid calculation of electronic energies and energy gradients for a small molecular structure with a given charge and spin state. Sparrow itself is able to calculate energies, gradients with respect to nuclear coordinates, and Hessian matrices (for vibrational frequencies and normal modes). More advanced calculations such as structure optimizations and transition state searches can be done through SCINE ReaDuct.

Current Features

  • MNDO-type models: MNDO(/d), AM1, AM1*, RM1, PM3, PM6
  • DFTB models: non-SCC DFTB, SCC-DFTB, DFTB3


SCINE Sparrow is distributed as an open source code. Visit our GitHub page to download it.

Future Releases

  • OMx models: OM1, OM2, OM3
  • HF-NDDO calculations
  • Semiclassical dispersion corrections
  • CISE approach (see this reference for more information)
  • Periodic boundary conditions


See the manual for introductory examples and a detailed documentation of the functionality of SCINE Sparrow. Documentation of the library API is available separately for the C++ library and its Python bindings module.


Despite intense testing of the program, questions may arise with respect to the usage of SCINE Sparrow. Do not hesitate to contact the developers via in case of any questions and suggestions.


  • Primary reference for Sparrow 5.0.0:
    F. Bosia, T. Husch, C. H. Müller, S. Polonius, J.-G. Sobez, M. Steiner, J. P. Unsleber, A. C. Vaucher, T. Weymuth, M. Reiher, "qcscine/sparrow: Release 5.0.0 (Version 5.0.0)", Zenodo, 2023. DOI
  • Presentation of the formalism of MNDO-type and OMx models:
    T. Husch, A. C. Vaucher, M. Reiher, "Semiempirical Molecular Orbital Models Based on the Neglect of Diatomic Differential Overlap Approximation", Int. J. Quantum Chem., 2018, 118, e25799. DOI
  • Presentation of HF-NDDO and CISE:
    T. Husch, M. Reiher, "Comprehensive Analysis of the Neglect of Diatomic Differential Overlap Approximation", J. Chem. Theory Comput., 2018, 14, 5169. DOI
  • Presentation of DFTB approaches:
    M. Elstner, G. Seifert, "Density functional tight binding", Phil. Trans. R. Soc. A, 2014, 371, 20120483. DOI