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Maykel L. González-Martínez

Quasi-classical statistico-dynamical description of polyatomic photo-dissociations: State-resolved distributions. Maykel L. González-Martínez. 6 th IMP, Feb. 1-5, 2010 . C. Habana. OUTLINE. 1. MOTIVATION 2. QUASI-CLASSICAL TRAJECTORY METHOD - ANGLE-ACTIONS & CARTESIAN COORDINATES

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Maykel L. González-Martínez

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  1. Quasi-classical statistico-dynamical description of polyatomic photo-dissociations: State-resolved distributions Maykel L. González-Martínez 6th IMP, Feb. 1-5, 2010. C. Habana

  2. OUTLINE 1. MOTIVATION 2. QUASI-CLASSICAL TRAJECTORY METHOD - ANGLE-ACTIONS & CARTESIAN COORDINATES - ECCPST 3. RESULTS - CH2CO  CH2 + CO… P(Etrans; jCO) distributions 4. SUMMARY & PERSPECTIVES 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  3. WHAT, WHY…? (OBJECT) 3- to 4-atom systems: Highly detailed experimental results First-principles amazingly-accurate theoretical predictions Planetary atmospheres, interstellar media 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  4. WHAT, WHY…? (OBJECT) Molecules of biological interest‏ 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  5. WHAT, WHY…? (OBJECT) Nano-objects 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  6. WHAT, WHY…? (OBJECT) Clusters 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  7. ‘Simplicity’ Extensivity WHAT, WHY…? (METHOD) Uni-, bi-molecular reactions, etc… Relatively low computational expense Prediction (‘smart’ influence)‏ High interpretative power, intuition… 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  8. Quasi-Classical Trajectory Method (QCTM)‏ t = 0 1.- (QC)initial conditions 0< t < Tmax (R ≤ Rmax) 2.-Hamilton/Newton equations of motion Ntraj = Ntot 3.- Statistics: From microscopic variables to observables 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  9. Unimolecular dissociation of ketene 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheory Results Conclusions

  10. RESULTS: Eexc < Eth(S0)  barrier (T1) Eexc~ Eth(S0) + 200 cm-1 Pdiss(S0) ~ 80% ↑Eexc: loose tight TS Effective barrierless polyatomic unimolecular reaction in a single PES Eb ~ few hundred cm-1 ΔST≈ 3150 cm-1 (Reproduced from I. -C. Chen, et al J. Chem. Phys.89, 314 (1988)‏) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  11. A. V. Komissarov et al. J. Chem. Phys.124, 014303 (2006)‏ RESULTS: ketene… P(ETrans; jCO) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  12. J. Chem. Phys.126, 041102 (2007)‏ A. A. Hoops et al. J. Chem. Phys.114, 9020 (2001)‏ 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  13. J. Chem. Phys.126, 041102 (2007)‏ RESULTS: NCO, P(ETrans) ‘explained’… 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  14. QCTM (+ GW): application to polyatomics Some problems… Microcanonical distribution at the TS GW requires ~ 10 times more trajectories/vibration… 104! • Angle-action variables • Idealfor initial conditions • Not ideal for propagation • Preferablefor final statistics • Cartesian coordinates • Not ideal for initial conditions • Idealfor propagation • OKfor final statistics No general transformation from AA to CC! 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  15. J. Chem. Phys.130, 114103 (2009)‏ RESULTS: photo-fragmentation of ketene 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  16. J. Chem. Phys.130, 114103 (2009)‏ CO(x4) CH2(- - x3) <asym. stretch> CH2(x1 - -) <scissor> CH2(- x2 -) <sym. stretch> 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  17. J. Chem. Phys.130, 114103 (2009)‏ k1<j1proj.> j1<CH2 rot.> j2<CO rot.> l <tot. orbital> Jz<Jproj.> J<tot. ang. momentum> 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  18. QCTM: Exit-channel corrected PST Hamilton-Brumer… I. Hamilton and P. Brumer, J. Chem. Phys.82, 595(1985) Microcanonical distribution at the products Hipothesis: Time-reversed dynamics yields MC ‘distro’ at TS accepted (t’  -t) rejected 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  19. QCTM: Exit-channel corrected PST Some advantages… Partitioning into product normal modes Threshold behavior Initial conditions  R | TS  flexibly (re-)defined No discretizing + no binning/weighting at t = Tmax Avoids the strong interaction region 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  20. Phys. Chem. Chem. Phys.12, 115 (2010) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  21. Phys. Chem. Chem. Phys.12, 115 (2010) QCTM: A modification to the PES 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  22. Phys. Chem. Chem. Phys.12, 115 (2010) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  23. Phys. Chem. Chem. Phys.12, 115 (2010) QCTM: How to ‘add’ the rotational resolution? 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  24. Phys. Chem. Chem. Phys.12, 115 (2010) Least-biased Quantum ET ET = E - hw/2 - Bvj(j+1) j = 2 j = 0 QCTM: P(ETrans; v) inABC A + BC(v) hn Least-biased Quantum with convolution Least-biased Classical with convolution P(ET) ET or ET = E - ‘exact’ ro-vibrational energy 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  25. Phys. Chem. Chem. Phys.12, 115 (2010) QCTM Final curve= LB quantum with convolution LB quantum with convolution Ratio = LB classical with convolution LB classical with convolution QCTM ET QCTM: P(ETrans; v) inABC A + BC(v) hn 1 P(ET) ET 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  26. Phys. Chem. Chem. Phys.12, 115 (2010) QCTM: How to ‘add’ the rotational resolution? 6th IMP, Feb. 1-5, 2010. C. Habana Intro Motivation Theory Results Conclusions

  27. Phys. Chem. Chem. Phys.12, 115 (2010) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  28. Phys. Chem. Chem. Phys.12, 115 (2010) 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheoryResults Conclusions

  29. SUMMARY & PERSPECTIVES • Angle-action variables to Cartesian coordinates for polyatomics • Problems in S0 PES of CH2CO • Alternative methodology to apply QCTM to polyatomics: • (1) t = 0: angle-actions to Cartesian coordinates; • (2) 0 < t < Tmax: ‘association’ perspective (Hamilton & Brumer); • (3) t = Tmax: QC formulae to ‘insert’ rotational resolution. • (1)+(2)+(3) = ¡Ro-vibrational resolution without binning/weighting! 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheory Results Conclusions

  30. SUMMARY & PERSPECTIVES • New ab initio PES for CH2CO(S0) • PESs y aplication to C2H2 C2H + H • ECCPST to direct processes • Multi-PES reactions 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheory Results Conclusions

  31. Prof. Jesús Rubayo Soneira InSTEC, C. Habana, CUBA. Prof. Jean-Claude Rayez ISM, Bordeaux, FRANCE. Dr. Pascal Larrégaray ISM, Bordeaux, FRANCE. Dr. Laurent Bonnet ISM, Bordeaux, FRANCE. COLLABORATORS 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheory Results Conclusions

  32. PROJECTS • Inter-University Agreement on International Joint Doctorate Supervision between the Instituto Superior de Tecnologías y Ciencias Aplicadas (CUBA) and the Université Bordeaux 1 (FRANCE)‏ • PNCB/2/04 project of the Departamento de Física General del Instituto Superior de Tecnologías y Ciencias Aplicadas (CUBA) MANY THANKS FOR YOUR ATTENTION 6th IMP, Feb. 1-5, 2010. C. Habana Intro MotivationTheory Results Conclusions

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