All mode dynamics at the conical intersection of an octa-atomic molecule: Multi-configuration time-dependent Hartree (MCTDH) investigation on the butatriene cation

The ground state and the first excited electronic states of the octa-atomic butatriene cation (C4H4+) exhibit a multidimensional conical intersection. This intersection is energetically low lying and is located in the vicinity of the Franck–Condon region of the neutral molecule’s ground state. The conical intersection thus dominates the nuclear dynamics in ionization processes of this molecule. This is a particularly interesting example of vibronic coupling, introducing what appears to be a new, structured band into the energy spectrum. In this work, the potential energy surfaces and their intersection are investigated by ab initio methods. A diabatic model Hamiltonian including all possible linear, quadratic and bilinear vibronic coupling terms is introduced, with coupling constants determined by a fit to the ab initio data. The nuclear dynamics of all 18 vibrational modes is then evaluated by propagating the wave packet using the multi-configuration time-dependent Hartree method. Finally, the photoelect...

[1]  A. Jansen,et al.  Ten-dimensional wave packet simulations of methane scattering , 1998, physics/0106025.

[2]  M. Klessinger.  Konische Durchdringungen und der Mechanismus von Singulett-Photoreaktionen , 1995 .

[3]  G. Stock.  Classical description of ultrafast internal conversion processes. The benzene cation , 1994 .

[4]  E. Davidson.  Global topology of triatomic potential surfaces , 1977 .

[5]  Lorenz S. Cederbaum,et al.  One-body Green's function for atoms and molecules: theory and application , 1975 .

[6]  L. Cederbaum,et al.  Ground state dynamics of NO3: Multimode vibronic borrowing including thermal effects , 1994 .

[7]  R. Kosloff,et al.  Time‐dependent photodissociation of methyl iodide with five active modes , 1994 .

[8]  S. Mahapatra,et al.  Femtosecond wavepacket dynamics on strongly coupled potential energy surfaces , 2000 .

[9]  H. Werner,et al.  Characterization of the S1–S2 conical intersection in pyrazine using ab initio multiconfiguration self‐consistent‐field and multireference configuration‐interaction methods , 1994 .

[10]  M. Beck,et al.  The multiconfiguration time-dependent Hartree (MCTDH) method: A highly efficient algorithm for propa , 1999 .

[11]  G. Worth,et al.  The Ã2E/B̃2B2Photoelectron Bands of Allene beyond the Linear Coupling Scheme: An ab Initio Dynamical Study Including All Fifteen Vibrational Modes† , 2001 .

[12]  L. Cederbaum,et al.  Strong vibronic coupling effects in ionization spectra: The “mystery band” of butatriene , 1977 .

[13]  Hans-Dieter Meyer,et al.  An efficient and robust integration scheme for the equations of motion of the multiconfiguration time-dependent Hartree (MCTDH) method , 1997 .

[14]  Uwe Manthe,et al.  Accurate quantum calculations of thermal rate constants employing MCTDH: H2+OH→H+H2O and D2+OH→D+DOH , 1998 .

[15]  M. Beck,et al.  Extracting accurate bound-state spectra from approximate wave packet propagation using the filter-diagonalization method , 1998 .

[16]  G. Worth,et al.  Molecular dynamics of pyrazine after excitation to the S2 electronic state using a realistic 24-mode model Hamiltonian , 1999 .

[17]  V. Engel.  The calculation of autocorrelation functions for spectroscopy , 1992 .

[18]  U. Manthe,et al.  Dynamics on potential energy surfaces with a conical intersection: Adiabatic, intermediate, and diabatic behavior , 1990 .

[19]  L. Cederbaum,et al.  Theoretical investigation of Jahn–Teller and pseudo-Jahn–Teller coupling effects on the photoelectron spectrum of allene , 1999 .

[20]  Hans-Dieter Meyer,et al.  Efficiently computing bound-state spectra: A hybrid approach of the multi-configuration time-dependent Hartree and filter-diagonalization methods , 2001 .

[21]  G. Diercksen,et al.  Ionization potentials of ethylene, allene and butatriene by a green function method , 1976 .

[22]  G. Worth,et al.  Relaxation of a system with a conical intersection coupled to a bath: A benchmark 24-dimensional wave packet study treating the environment explicitly , 1998 .

[23]  H. Köppel,et al.  Aspects of dissipative electronic and vibrational dynamics of strongly vibronically coupled systems , 1990 .

[24]  U. Manthe,et al.  Dissociation and predissociation on coupled electronic potential energy surfaces: A three‐dimensional wave packet dynamical study , 1991 .

[25]  P. Schleyer.  Encyclopedia of computational chemistry , 1998 .

[26]  Vladimir A. Mandelshtam,et al.  A low-storage filter diagonalization method for quantum eigenenergy calculation or for spectral analysis of time signals , 1997 .

[27]  L. Cederbaum,et al.  Vibronic coupling effects in the ozone cation , 1992 .

[28]  Lorenz S. Cederbaum,et al.  Multimode Molecular Dynamics Beyond the Born‐Oppenheimer Approximation , 2007 .

[29]  I. Matsubara,et al.  Butatriene: Infrared and Raman spectra and structure , 1966 .

[30]  G. Stock,et al.  Resonance Raman spectroscopy of the S1 and S2 states of pyrazine: Experiment and first principles calculation of spectra , 1995 .

[31]  P. Dirac.  Note on Exchange Phenomena in the Thomas Atom , 1930, Mathematical Proceedings of the Cambridge Philosophical Society.

[32]  H. C. Longuet-Higgins,et al.  Intersection of potential energy surfaces in polyatomic molecules , 1963 .

[33]  W. Domcke,et al.  Path‐integral treatment of multi‐mode vibronic coupling , 1994 .

[34]  H. Köppel.  New ultrafast nonradiative decay mechanism in the benzene radical cation , 1993 .

[35]  A. Jansen,et al.  MCTDH study of CH4 dissociation on Ni(111) , 1995 .

[36]  J. Toft,et al.  AN ELECTRON DIFFRACTION INVESTIGATION OF THE MOLECULAR STRUCTURE OF BUTATRIENE , 1961 .

[37]  M. Ehara,et al.  Multiconfiguration time‐dependent Hartree (MCTDH) study on rotational and diffractive inelastic molecule‐surface scattering , 1996 .

[38]  Hua Guo,et al.  Four-dimensional quantum dynamics of the CH3I/MgO photodissociation , 1995 .

[39]  D. Neuhauser.  Bound state eigenfunctions from wave packets: Time→energy resolution , 1990 .

[40]  L. Cederbaum,et al.  Topology and dynamics of vibronically coupled potential energy surfaces : general aspects and application to the ozone cation , 1993 .

[41]  Hans-Dieter Meyer,et al.  A numerical study on the performance of the multiconfiguration time-dependent Hartree method for density operators , 2000 .

[42]  H. Schaefer.  Methods of Electronic Structure Theory , 1977 .

[43]  H. Meyer,et al.  Reaction cross sections for the H+D2(ν=0,1) system for collision energies up to 2.5 eV: A multiconfiguration time-dependent Hartree wave-packet propagation study , 1999 .

[44]  L. Radom,et al.  The photoelectron spectrum of butatriene , 1974 .

[45]  Lorenz S. Cederbaum,et al.  Multiconfigurational time‐dependent Hartree study of complex dynamics: Photodissociation of NO2 , 1992 .

[46]  U. Manthe,et al.  Wave‐packet dynamics within the multiconfiguration Hartree framework: General aspects and application to NOCl , 1992 .

[47]  U. Manthe,et al.  The multi-configurational time-dependent Hartree approach , 1990 .

[48]  H. Köppel,et al.  Multiple surface intersections and strong nonadiabatic coupling effects between the D̃ 2E1u and Ẽ 2B2u states of C6H6 , 1997 .

[49]  Potential energy surface crossings in organic photochemistry , 1996 .