2015/10/31 by Vincent Pohl, Jean Christophe Tremblay · 1 citation
Chemistry · Mathematics · Physics and Astronomy · #Adiabatic process #Advanced Chemical Physics Studies #Ansatz #Born–Oppenheimer approximation #Density functional theory #Electronic density #Electronic structure #Excited state #Geometry #Ground state #Mathematics #Molecular Spectroscopy and Structure #Physics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Symmetry (geometry) #Vibronic coupling #physics.chem-ph #quant-ph
paper · pdf · doi:10.1103/physreva.93.012504
published as Phys. Rev. A 93, 012504 (2016)
arxiv created 2015/11/30 · openalex publication_date 2016/01/12 · arxiv updated 2016/04/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Born-Oppenheimer approximation leads to the counterintuitive result of a vanishing electronic flux density upon vibrational dynamics in the electronic ground state. To circumvent this long known issue, we propose using pairwise antisymmetrically translated vibronic densities to generate a symmetric electronic density that can be forced to satisfy the continuity equation approximately. The so-called Born-Oppenheimer broken-symmetry ansatz yields all components of the flux density simultaneously while requiring only knowledge about the nuclear quantum dynamics on the electronic adiabatic ground-state potential energy surface. The underlying minimization procedure is transparent and computationally inexpensive, and the solution can be computed from the standard output of any quantum chemistry program. Taylor series expansion reveals that the implicit electron dynamics originates from nonadiabatic coupling to the explicit Born-Oppenheimer nuclear dynamics. Our approach is applied to the H2+ molecular ion vibrating in its 2\mathrm\ensuremathΣg+ ground state. The electronic flux density is found to have the correct nodal structure and symmetry properties at all times.