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Dynamics of clusters and molecules in strong electromagnetic fields: A TDDFT-MD approach Ionization Environment Time-resolved dynamics Laser Projectile.

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Presentation on theme: "Dynamics of clusters and molecules in strong electromagnetic fields: A TDDFT-MD approach Ionization Environment Time-resolved dynamics Laser Projectile."— Presentation transcript:

1 Dynamics of clusters and molecules in strong electromagnetic fields: A TDDFT-MD approach Ionization Environment Time-resolved dynamics Laser Projectile Fondamental studies of mechanisms of irradiation and response of clusters coupled with environment

2 model-potential electrons TDDFT-MD Gen. QM/MM Dyn. polar. TDCI Statics Dynamics ElectronsEnvironment Methods on the market Car-Parinello, BO/MDCar-Parinello, BO QM/MM model-potential electrons Today: CNOH molecules + H 2 O "environment" Na n @Ar,Ne,Kr @ MgO

3 Na n n valence e - n ions (Na + ) TDLDA + ADSIC MD-TDDFT(LDA) non-adiab. dynamics (≠BO) explicit pseudopotentials TDDFT-MD laser projectile Today, ions are: C 4+, O 6+, N 7+, H +

4 Numerical details represented on 3D grid: 48 3, 64 3, 72 3, 96 3, … Goedecker-like (non-local) dt = 0.5 as 50 fs for H 2 O 64 3 54 h70h 96 2 x 72138 h234 h fixed ionsmoving ions propagation: time-splitting Verlet algorithm box size Home-made codes

5 (Time-resolved) observables from electrons: optical response cloud deformation, shape, localization ionization > number of emitted e - > kinetic E spectrum of emitted e - > angular distribution of emitted e - > level depletion from ions: potential and kinetic (temperature) E global deformation and shape bond lengths, energies Today: projectile + H 2 O laser + (H 2 O) H 3 O + laser/proj. + C 2 H 4

6 water = electronic insulator gap  10 eV 0.1 au threshold Why TDLDA-MD ? projectile + H 2 O charge velocity 0 adiab. sudden cf. J. Kohanoff

7 adiab. Why TDLDA-MD ? charge velocity 0 "fixed e - " + ionic MD sudden e - TDDFT + fixed ions ? ? Which theory for: dynamical description of irradiation and response of electrons and ions ? ? ?  H + + H 2 O C + H 2 O

8 H + + H 2 O, low v

9 C + H 2 O, high v

10 Laser irradiation of (H 2 O)H 3 O + E pol I 0 =10 13 W/cm 2 FWHM=20 fs frequency scan IP=-20.6 eV off-resonant but... off-resonant vibrations 2

11 C 2 H 4 : optical response IP: -11.7 eV 6.8 eV Yabana, Bertsch (2001) Fourier Transform 8.16 eV136 eV

12 Laser pol. I = 10 13 Wcm -2 FWHM = 20 fs C 2 H 4 : laser irradiation below resonanceson resonancewell above resonance

13 Ionization (level depletion) from a given electronic level Compare cases with similar (small) net ionization C 2 H 4 : ionization mechanisms

14 Ionization Environment Time resolved dynamics Laser Projectile Dynamical description of irradiation and response of electrons and ions with coupling to environment Irradiation of clusters and molecules by intense electro- magnetic fields Environment - Hierarchical model Dynamical QM/MM - Na@Ar, Kr, Ne - Na @ MgO - Na@H 2 O in the oven - C, N, O @ H 2 O in near future - C, N, O @ H 2 O @Ar in future Dynamics of ionization - Self Interaction problem (SIC) - Benchmark TDSIC calculations - Simple approximations in the oven - Dynamical correlations in the future (electronic transport) Time resolved dynamics Key importance of non adiabatic electron-ion dynamics for understanding mechanisms Thanks to E. Suraud, P.-G. Reinhard, Z.P. Wang, U. Ndongmouo, J. Messud S. Vidal, and you for your attention !


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