Recent Developments in the Electron Nuclear Dynamics Theory: from Coherent-States and Density-Functional-Theory Implementations to Applications in Cancer Proton Therapy
Jorge A. Morales
Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409
The electron nuclear dynamics (END) theory [1] provides a time-dependent, variational, and non-adiabatic approach to chemical dynamics that requires no predetermined potential energy surfaces during simulations. END dynamical equations are obtained from the time-dependent variational principle applied to a trial wavefunction represented via coherent states (CS) [1]. The simplest-level END (SLEND) [1] describes the nuclei via classical mechanics and the electrons via a single-determinantal wavefunction. In the SLEND framework, three interrelated developments implemented in our own code PACE (Python Accelerated Coherent-states Electron-nuclear dynamics) will be discussed [2-4]:
1. The use of different types of CS [4] to describe all types of particles (nuclei and electrons) and degrees of freedom (translational, rotational, vibrational and electronic). Rotational and vibrational CS sets permit reconstructing quantum excitation probabilities from the SLEND nuclear classical dynamics. Electronic CS sets [2] underlie a valence-bond approach to the charge-equilibration model based on the Sanderson principle of electronegativity equalization.
2. A new time-dependent Kohn-Sham density-functional-theory (KSDFT) dynamics method [3] in the END framework: The END/KSDFT method.
3. A new implementation of effective core potentials into SLEND and END/KSDT.
These developments allow feasible and accurate simulations of numerous chemical reactions including: (A) proton-molecule reactions undergoing rovibrational excitations and energy and electron transfers [4-6]; (B) high-energy proton reactions with aqueous clusters and DNA components that are essential processes in cancer proton therapy; and (C) chemical reactions involving large reactants, such as Diels-Alder and SN2 reactions.
References:
[1] E. Deumens, A. Diz, R. Longo, Y. Öhrn, Rev. Mod. Phys. 66 (1994) 917.
[2] J. A. Morales, J. Phys. Chem. A 113 (2009) 6004.
[3] S. A. Perera, P. M. McLaurin, T. V. Grimes, J. A. Morales, Chem. Phys. Lett. 496 (2010) 188.
[4] J. A. Morales, Molecular Physics 108 (2010) 3199.
[5] C. Stopera, B. Maiti, T. V. Grimes, P. M. McLaurin, J. A. Morales, The Journal of Chemical Physics 134 (2011) 224308.
[6] C. Stopera, B. Maiti, T. V. Grimes, P. M. McLaurin, J. A. Morales, The Journal of Chemical Physics 136 (2012) 054304.
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Posted:
4/9/2012
Originator:
Debra Boyce
Email:
debra.boyce@ttu.edu
Department:
Physics
Event Information
Time: 3:00 PM - 5:00 PM
Event Date: 4/12/2012
Location:
Refreshments in Science 103 at 3:00, Talk at 3:40 in Science 234
Categories
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