Relaxation dynamics in quantum dissipative systems: The microscopic effect of intramolecular vibrational energy redistribution

被引:9
作者
Uranga-Pina, L. [1 ,2 ]
Tremblay, J. C. [2 ]
机构
[1] Univ Habana, Fac Fis, Havana 10400, Cuba
[2] Free Univ Berlin, Inst Chem & Biochem, D-14195 Berlin, Germany
关键词
HOLE PAIR MECHANISM; ELECTRONIC EXCITATIONS; SURFACE-DIFFUSION; CO; DESORPTION; SCATTERING; NO; PHOTODESORPTION; SPECTROSCOPY; TRANSLATION;
D O I
10.1063/1.4892376
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We investigate the effect of inter-mode coupling on the vibrational relaxation dynamics of molecules in weak dissipative environments. The simulations are performed within the reduced density matrix formalism in the Markovian regime, assuming a Lindblad form for the system-bath interaction. The prototypical two-dimensional model system representing two CO molecules approaching a Cu(100) surface is adapted from an ab initio potential, while the diatom-diatom vibrational coupling strength is systematically varied. In the weak system-bath coupling limit and at low temperatures, only first order non-adiabatic uni-modal coupling terms contribute to surface-mediated vibrational relaxation. Since dissipative dynamics is non-unitary, the choice of representation will affect the evolution of the reduced density matrix. Two alternative representations for computing the relaxation rates and the associated operators are thus compared: the fully coupled spectral basis, and a factorizable ansatz. The former is well-established and serves as a benchmark for the solution of Liouville-von Neumann equation. In the latter, a contracted grid basis of potential-optimized discrete variable representation is tailored to incorporate most of the inter-mode coupling, while the Lindblad operators are represented as tensor products of one-dimensional operators, for consistency. This procedure results in a marked reduction of the grid size and in a much more advantageous scaling of the computational cost with respect to the increase of the dimensionality of the system. The factorizable method is found to provide an accurate description of the dissipative quantum dynamics of the model system, specifically of the time evolution of the state populations and of the probability density distribution of the molecular wave packet. The influence of intra-molecular vibrational energy redistribution appears to be properly taken into account by the new model on the whole range of coupling strengths. It demontrates that most of the mode mixing during relaxation is due to the potential part of the Hamiltonian and not to the coupling among relaxation operators. (C) 2014 AIP Publishing LLC.
引用
收藏
页数:15
相关论文
共 60 条
[21]   A high resolution helium atom scattering and far infrared study of the dynamics and the lateral potential energy surface of CO molecules chemisorbed on Cu(001) [J].
Graham, AP ;
Hofmann, F ;
Toennies, JP ;
Williams, GP ;
Hirschmugl, CJ ;
Ellis, J .
JOURNAL OF CHEMICAL PHYSICS, 1998, 108 (18) :7825-7834
[22]   Electronic structure and catalysis on metal surfaces [J].
Greeley, J ;
Norskov, JK ;
Mavrikakis, M .
ANNUAL REVIEW OF PHYSICAL CHEMISTRY, 2002, 53 :319-348
[23]   Short-time Chebyshev propagator for the Liouville-von Neumann equation [J].
Guo, H ;
Chen, RQ .
JOURNAL OF CHEMICAL PHYSICS, 1999, 110 (14) :6626-6634
[24]  
Hammer B, 2000, ADV CATAL, V45, P71
[25]   VIBRATIONAL-RELAXATION ON METAL-SURFACES - MOLECULAR-ORBITAL THEORY AND APPLICATION TO CO/CU(100) [J].
HEAD-GORDON, M ;
TULLY, JC .
JOURNAL OF CHEMICAL PHYSICS, 1992, 96 (05) :3939-3949
[26]   ELECTRONIC DAMPING OF ATOMIC AND MOLECULAR VIBRATIONS AT METAL-SURFACES [J].
HELLSING, B ;
PERSSON, M .
PHYSICA SCRIPTA, 1984, 29 (04) :360-371
[27]   ADSORBATE-SUBSTRATE RESONANT INTERACTIONS OBSERVED FOR CO ON CU(100) IN THE FAR INFRARED [J].
HIRSCHMUGL, CJ ;
WILLIAMS, GP ;
HOFFMANN, FM ;
CHABAL, YJ .
PHYSICAL REVIEW LETTERS, 1990, 65 (04) :480-483
[28]   High-resolution helium atom time-of-flight spectroscopy of low-frequency vibrations of adsorbates [J].
Hofmann, F ;
Toennies, JP .
CHEMICAL REVIEWS, 1996, 96 (04) :1307-1326
[29]   Ab initio diffusional potential energy surface for CO chemisorption on Pd{110} at high coverage: Coupled translation and rotation [J].
Hu, P ;
King, DA ;
Crampin, S ;
Lee, MH ;
Payne, MC .
JOURNAL OF CHEMICAL PHYSICS, 1997, 107 (19) :8103-8109
[30]   ELECTRON-HOLE PAIR MECHANISM FOR EXCITATION OF INTRAMOLECULAR VIBRATIONS IN MOLECULE SURFACE SCATTERING [J].
KASAI, H ;
OKIJI, A .
SURFACE SCIENCE, 1990, 225 (1-2) :L33-L38