Texas Tech University


VENUS code was developed by the late Prof. Bill Hase

VENUS is a general chemical dynamics computer program for performing classical trajectory simulations and a legacy of Prof. William L. Hase. The program uses analytic functions to represent the potential energy surface (PES) for the chemical system. The analytic functions include reactive potentials which allow bond rupture and formation and non-reactive molecular mechanical (MM) potentials. The program includes a variety of options for choosing initial conditions (such as rotation, vibration, and translation energies) for an ensemble of trajectories to represent both unimolecular and bimolecular reactions (Adv. Chem. Phys., 1999, 105, 171–201).

In the widely used version of VENUS96C, as well as in the later developments (VENUS05), the initial conditions of reactant(s) are randomly chosen from a microcanonical, a canonical, or a quantum microcanonical ensemble with semiclassical (for a diatomic molecule), classical, and quasi-classical (for a polyatomic molecule) sampling methods. The trajectories are integrated by methods with high precisions, including a Symplectic integrator and a Hessian-based predictor-corrector integrator (J. Chem. Phys., 2007, 126, 044105). The trajectories are concluded when reaching definition of “products”, where their final Cartesian momenta and co-ordinates are transformed to experimental observables.

VENUS/NWCHEM/MOPAC/DFTB+ is a classical trajectory direct dynamics computer program, which provides an interface of VENUS and the NWChem (Computer Physics Comm., 2014, 185, 1074-1080), MOPAC (J. Phys. Chem. C, 2018, 122, 29368-29379) and DFTB+(J. Chem. Phys., 2020, 153, 184702) electronic structure computer programs. These combinations allow performing QM and QM+MM direct dynamics simulation (J. Am. Chem. Soc., 2017, 139, 3570-3590.; Rev. Comput. Chem., 2003, 19, 79-146).

VENUS-SCIVR is an expansion of VENUS implementing the multiple coherent states semiclassical initial value representation (MC-SC-IVR) method with collaboration with Prof. Michele Ceotto (University of Milan). With the VENUS-SCIVR package, one may obtain anharmonic quantum vibrational power spectra and frequencies at semiclassical level with swarms of classical trajectories.

VENUS-Condensed Phase can be used to investigate how potential energy surface (PES) properties and collision attributes affect intermolecular energy transfer (IET). The simulations based on accurate intermolecular potentials between the excited molecule and the bath gas, and between the bath gases may be used to obtained accurate IET dynamics and make rigorous comparisons with experiment. Also of interest are simulations which investigate the role of the bath density (pressure) on energy transfer processes for the hot molecule J. Chem. Phys., 2014, 140, 194103.


  1. Hase, W. L.; Duchovic, R. J.; Hu, X.; Komornicki, A.; Lim, K. F.; Lu, D.-H.; Peslherbe, G. H.; Swamy, K. N.; Vande Linde, S. R.; Varandas, A., Wang, H.; Wolf, R. J. VENUS96: A general chemical dynamics computer program, Quantum Chemical Program Exchange (QCPE) Bulletin1996, 16(4), 671.
  2. Hu, X.; Hase, W. L.; Pirraglia, T. Vectorization of the General Monte Carlo Classical Trajectory Program VENUS. J. Comput. Chem.  1991, 12, 1014– 1024. DOI: 10.1002/jcc.540120814


  1. Lourderaj, U.; Sun, R.; Kohale, S. C.; Barnes, G. L.; de Jong, W. A.; Windus, T. L.; Hase, W. L. The VENUS/NWChem Software Package. Tight Coupling between Chemical Dynamics Simulations and Electronic Structure Theory. Comput. Phys. Commun. 2014, 185, 1074– 1080. DOI: 10.1016/j.cpc.2013.11.011


  1. Ma, X.; Di Liberto, G.; Conte, R.; Hase, W. L.; Ceotto, M. A quantum mechanical insight into SN2 reactions: Semiclassical Initial Value Representation calculations of the vibrational features of the Cl- + CH3Cl pre-reaction complex with VENUS suite of codes. J. Chem. Phys.2018, 149, 164113. DOI: 10.1063/1.5054399


VENUS Manual (PDF)

VENUS code can be requested by filling out the license agreement and emailing the form to the chair of the Department of Chemistry & Biochemistry, chemchair@ttu.edu.

VENUS License-Agreement

Additional VENUS Support
(Maintained by Dr. Riccard Spezia, Sorbonne Université)

Department of Chemistry & Biochemistry