Dynamics of clusters and moleculesin strong electromagnetic fields:
A TDDFT-MD approach
Ionization
Environment
Time-resolved dynamics
Laser
Projectile
Fondamental studies of mechanisms of irradiationand response of clusters coupled with environment
model-potential electrons
TDDFT-MD
Gen. QM/MMDyn. polar. TDCI
Sta
tics
Dyn
am
ics
ElectronsEnvironment
Methods on the market
Car-Parinello, BO/MDCar-Parinello, BO QM/MM
model-potential electrons
Today: CNOH molecules
+ H2O "environment"
Nan@Ar,Ne,Kr@ MgO
Nan
n valence e-
n ions (Na+)
TDLDA + ADSIC MD-TDDFT(LDA)non-adiab. dynamics
(≠BO)• explicit• pseudopotentials
TDDFT-MD
laserprojectile
Today, ions are: C4+, O6+, N7+, H+
Numerical details
represented on 3D grid: 483, 643, 723, 963, …
Goedecker-like (non-local)
dt = 0.5 as
50 fs for H2O
643 54 h 70h
962 x 72 138 h 234 h
fixed ions moving ions
propagation: time-splitting
Verlet algorithm
box size
Home-made codes
(Time-resolved) observables
from electrons: optical responsecloud deformation, shape, localizationionization
> number of emitted e-
> kinetic E spectrum of emitted e-
> angular distribution of emitted e-
> level depletion
from ions: potential and kinetic (temperature) Eglobal deformation and shapebond lengths, energies
Today: • projectile + H2O• laser + (H2O) H3O+
• laser/proj. + C2H4
water = electronic insulator gap 10 eV
0.1 au
threshold
Why TDLDA-MD ?
projectile + H2O
charg
e
velocity0
adiab.
sudden
cf. J. Kohanoff
adiab.
Why TDLDA-MD ?ch
arg
e
velocity0
"fixed e-" +
ionic MD
suddene- TDDFT
+fixed ions
??
Which theory for:dynamical description of
irradiation and response of
electrons and ions ?
?
?
H+ + H2O
C + H2O
H+ + H2O, low v
C + H2O, high v
Laser irradiation of (H2O)H3O+
Epol
I0=1013W/cm2
FWHM=20 fsfrequency scan
IP=-20.6 eV
off-resonant but...
off-resonant
vibrations
2
C2H4 : optical response
IP: -11.7 eV
6.8 eV
Yabana, Bertsch (2001)
Fourier Transform
8.16 eV 136 eV
Laser pol.I = 1013 Wcm-2
FWHM = 20 fs
C2H4 : laser irradiation
below resonances on resonance well above resonance
Ionization (level depletion) from a given electronic levelCompare cases with similar (small) net ionization
C2H4 : ionization mechanisms
Ionization
Environment
Time resolved dynamics
Laser
Projectile
Dynamical description of irradiationand 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@H2O in the oven- C, N, O @ H2O in near future- C, N, O @ H2O @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 dynamicsKey importance of non adiabaticelectron-ion dynamics for understanding mechanisms
Thanks toE. Suraud, P.-G. Reinhard,Z.P. Wang,U. Ndongmouo, J. MessudS. Vidal, andyou for your attention !
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