MNDO is a semiempirical quantum chemistry program written by Walter Thiel († 2019). Copyrights are now owned by his family, and scientific responsibility has been assumed by Prof. Dr. Frank Neese at the Max-Planck-Institut für Kohlenforschung in Mülheim an der Ruhr. While the program was available commercially in the past, we now follow an open source license model for non-commercial applications. Please see License form and Using Git and Gitea for further details.
In the center of program MNDO are semiempirical methods using orthogonalization corrections [1–6] which offer a much improved description of ground and excited states of organic molecules compared with traditional semiempirical models like MNDO , AM1  or PM3 .
For the description of excited states, two configuration interaction (CI) modules are available. One employs the Graphical Unitary Group Approach (GUGA)  for the evaluation of the CI Hamiltonian matrix elements and is designed for arbitarily high spin states and excitation levels using small active molecular orbital spaces . The other module implements a dedicated CI with single excitations for singlet and triplet spin states which is intended for using all molecular orbitals . For both approaches, a semi-analytical or fully analytical gradient is available [9,11–12].
Other modules implement algorithms to perform excited-state molecular dynamics (MD) using “fewest-switches” surface hopping , Born-Oppenheimer MD, and an optimizer for minima and transition states using hybrid delocalized coordinates (HDLC) .
Selected publicationsAll items in the following lists represent web links.
- P. O. Dral, X. Wu, W. Thiel, Semiempirical quantum-chemical methods with orthogonalization and dispersion corrections, J. Chem. Theory Comput. 15, 1743–1760 (2019).
- X. Wu, P. O. Dral, A. Koslowski, W. Thiel, Big data analysis of ab initio molecular integrals in the neglect of diatomic differential overlap approximation, J. Comput. Chem. 40, 638–649 (2019).
- P. O. Dral, X. Wu, L. Spörkel, A. Koslowski, W. Weber, R. Steiger, M. Scholten, W. Thiel, Semiempirical quantum-chemical orthogonalization-corrected methods: Theory, implementation, and parameters, J. Chem. Theory Comput. 12, 1082–1096 (2016).
- P. O. Dral, X. Wu, L. Spörkel, A. Koslowski, W. Thiel, Semiempirical quantum-chemical orthogonalization-corrected methods: Benchmarks for ground-state properties, J. Chem. Theory Comput. 12, 1097–1120 (2016).
- W. Weber, W. Thiel, Orthogonalization corrections for semiempirical methods, Theor. Chem. Acc. 103, 495–506 (2000).
- M. Kolb, W. Thiel, Beyond the MNDO model: Methodical considerations and numerical results, J. Comput. Chem. 14, 775–789 (1993).
- M. J. S. Dewar, W. Thiel, Ground states of molecules. 38. The MNDO method. Approximations and parameters, J. Am. Chem. Soc. 99, 4899–4907 (1977).
- J. Liu, W. Thiel, An efficient implementation of semiempirical quantum-chemical orthogonalization-corrected methods for excited-state dynamics, J. Chem. Phys. 148, 154103 (2018).
- J. Liu, A. Koslowski, W. Thiel, Analytic gradient and derivative couplings for the spin-flip extended configuration interaction singles method: Theory, implementation, and application to proton transfer, J. Chem. Phys. 148, 244108 (2018).
- A. Koslowski, M. E. Beck, W. Thiel, Implementation of a general multireference configuration interaction procedure with analytic gradients in a semiempirical context using the graphical unitary group approach, J. Comput. Chem. 24, 714–726 (2003).
- S. Patchkovskii, A. Koslowski, W. Thiel, Generic implementation of semi-analytical CI gradients for NDDO-type methods, Theor. Chem. Acc. 114, 84–89 (2005).
- S. Patchkovskii, W. Thiel, Analytical first derivatives of the energy for small CI expansions, Theor. Chem. Acc. 98, 1–4 (1997).
- E. Fabiano, T. W. Keal, W. Thiel, Implementation of surface hopping molecular dynamics using semiempirical methods, Chem. Phys. 349, 334–347 (2008).
- S. R. Billeter, A. J. Turner, W. Thiel, Linear scaling geometry optimisation and transition state search in hybrid delocalised internal coordinates, Phys. Chem. Chem. Phys. 2, 2177–2186 (2000).
Work by other authors
- M. J. S. Dewar, E. G. Zoebisch, E. F. Healy, J. J. P. Stewart, AM1: A new general purpose quantum mechanical molecular model, J. Am. Chem. Soc. 107, 3902–3909 (1985).
- J. J. P. Stewart, Optimization of parameters for semiempirical methods I. Method, J. Comput. Chem. 10, 209–220 (1989).
- I. Shavitt, The graphical unitary group approach and its application to direct configuration interaction calculations, in: J. Hinze (Ed.), The unitary group for the evaluation of electronic energy matrix elements, Lecture Notes in Chemistry 22, 51–99 (1981).