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MO: Fachverband Molekülphysik
MO 6: Theory of Molecular Dynamics
MO 6.3: Vortrag
Dienstag, 7. März 2017, 11:45–12:00, N 25
Non-Hermitian Surface Hopping — •Xing Gao1 and Walter Thiel2 — 1Max-Planck-Institut für Physik komplexer Systeme — 2Max-Planck-Institut für Kohlenforschung
It is quite a challenge to balance coherence and decoherence effects in non-adiabatic mixed quantum-classical dynamics such as Ehrenfest and surface hopping dynamics. Here we address this challenge by presenting a generalized non-Hermitian equation of motion (nH-EOM) which is derived using the Born-Huang expansion of the total wavefunction and the polar representation of the nuclear factor. Compared to standard trajectory surface hopping, the nH-EOM contains two additional terms, a skew symmetry term iΓ with dissipation operator Γ to account for decoherence and a renormalized kinetic-energy term to take care of phase shifts, without destroying the invariance to the choice of representation. Numerically, the nH-EOM can still be solved efficiently using a semiclassical approximation in the framework of Tully's fewest-switches surface hopping (FSSH) algorithm. Applications to molecular collision model Hamiltonians demonstrate improved performance over the standard FSSH approach, through comparison to exact quantum results.