scholarly journals Hierarchical Equations-of-Motion Method for Momentum System–Bath Coupling

2021 ◽  
Author(s):  
Maxim F. Gelin ◽  
Raffaele Borrelli ◽  
Lipeng Chen
Keyword(s):  
Equations Of Motion ◽  
Motion Method

ChemInform Abstract: ELECTRONIC EXCITATIONS OF BENZENE FROM THE EQUATIONS OF MOTION METHOD

1974 ◽  
Vol 5 (27) ◽  
pp. no-no
Author(s):  
JOHN B. ROSE ◽  
TAI-ICHI SHIBUYA ◽  
VINCENT MCKOY
Keyword(s):  
Equations Of Motion ◽  
Electronic Excitations ◽  
Motion Method

scholarly journals Electronic excitations of benzene from the equations of motion method

1974 ◽  
Vol 60 (7) ◽  
pp. 2700-2702 ◽  
Author(s):  
John B. Rose ◽  
Tai‐Ichi Shibuya ◽  
Vincent McKoy
Keyword(s):  
Equations Of Motion ◽  
Electronic Excitations ◽  
Motion Method

scholarly journals Dissipative dynamics at conical intersections: simulations with the hierarchy equations of motion method

2016 ◽  
Vol 194 ◽  
pp. 61-80 ◽  
Author(s):  
Lipeng Chen ◽  
Maxim F. Gelin ◽  
Vladimir Y. Chernyak ◽  
Wolfgang Domcke ◽  
Yang Zhao
Keyword(s):  
Relaxation Time ◽  
Electronic State ◽  
Equations Of Motion ◽  
Equation Of Motion ◽  
Harmonic Oscillators ◽  
Conical Intersection ◽  
Coherent Motion ◽  
Conical Intersections ◽  
Dissipative Dynamics ◽  
Motion Method

The effect of a dissipative environment on the ultrafast nonadiabatic dynamics at conical intersections is analyzed for a two-state two-mode model chosen to represent the S2(ππ*)–S1(nπ*) conical intersection in pyrazine (the system) which is bilinearly coupled to infinitely many harmonic oscillators in thermal equilibrium (the bath). The system–bath coupling is modeled by the Drude spectral function. The equation of motion for the reduced density matrix of the system is solved numerically exactly with the hierarchy equation of motion method using graphics-processor-unit (GPU) technology. The simulations are valid for arbitrary strength of the system–bath coupling and arbitrary bath memory relaxation time. The present computational studies overcome the limitations of weak system–bath coupling and short memory relaxation time inherent in previous simulations based on multi-level Redfield theory [A. Kühl and W. Domcke, J. Chem. Phys. 2002, 116, 263]. Time evolutions of electronic state populations and time-dependent reduced probability densities of the coupling and tuning modes of the conical intersection have been obtained. It is found that even weak coupling to the bath effectively suppresses the irregular fluctuations of the electronic populations of the isolated two-mode conical intersection. While the population of the upper adiabatic electronic state (S2) is very efficiently quenched by the system–bath coupling, the population of the diabatic ππ* electronic state exhibits long-lived oscillations driven by coherent motion of the tuning mode. Counterintuitively, the coupling to the bath can lead to an enhanced lifetime of the coherence of the tuning mode as a result of effective damping of the highly excited coupling mode, which reduces the strong mode–mode coupling inherent to the conical intersection. The present results extend previous studies of the dissipative dynamics at conical intersections to the nonperturbative regime of system–bath coupling. They pave the way for future first-principles simulations of femtosecond time-resolved four-wave-mixing spectra of chromophores in condensed phases which are nonperturbative in the system dynamics, the system–bath coupling as well as the field-matter coupling.

Equations-of-motion method and pairing correlations in odd-Anuclei

1980 ◽  
Vol 22 (6) ◽  
pp. 2555-2560 ◽  
Author(s):  
F. Andreozzi ◽  
A. Covello ◽  
A. Porrino
Keyword(s):  
Equations Of Motion ◽  
Pairing Correlations ◽  
Motion Method
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