Angledependent strongfield molecular ionization rates with tuned rangeseparated timedependent density functional theory
Strongfield ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionizationtriggered charge migration. Modeling ionization dynamics in molecular systems from firstprinciples can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require nonperturbative timedependent electronic structure methods. In this paper, we develop a timedependent density functional theory approach which uses a Gaussiantype orbital (GTO) basis set to capture strongfield ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a timedependent laser potential and a spatial nonHermitian complex absorbing potential which is projected onto an atomcentered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned rangeseparated functional LCPBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angledependent ionization), and the results are shown to quantitatively agree with timedependent Schrödinger equation and strongfieldmore »
 Authors:

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 Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemistry
 Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy
 Louisiana State Univ., Baton Rouge, LA (United States). Center for Computation and Technology, Dept. of Chemistry
 Publication Date:
 Grant/Contract Number:
 SC0012462
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Chemical Physics
 Additional Journal Information:
 Journal Volume: 145; Journal Issue: 9; Journal ID: ISSN 00219606
 Publisher:
 American Institute of Physics (AIP)
 Research Org:
 Louisiana State Univ., Baton Rouge, LA (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
 OSTI Identifier:
 1467880
 Alternate Identifier(s):
 OSTI ID: 1315846
Sissay, Adonay, Abanador, Paul, Mauger, François, Gaarde, Mette, Schafer, Kenneth J., and Lopata, Kenneth. Angledependent strongfield molecular ionization rates with tuned rangeseparated timedependent density functional theory. United States: N. p.,
Web. doi:10.1063/1.4961731.
Sissay, Adonay, Abanador, Paul, Mauger, François, Gaarde, Mette, Schafer, Kenneth J., & Lopata, Kenneth. Angledependent strongfield molecular ionization rates with tuned rangeseparated timedependent density functional theory. United States. doi:10.1063/1.4961731.
Sissay, Adonay, Abanador, Paul, Mauger, François, Gaarde, Mette, Schafer, Kenneth J., and Lopata, Kenneth. 2016.
"Angledependent strongfield molecular ionization rates with tuned rangeseparated timedependent density functional theory". United States.
doi:10.1063/1.4961731. https://www.osti.gov/servlets/purl/1467880.
@article{osti_1467880,
title = {Angledependent strongfield molecular ionization rates with tuned rangeseparated timedependent density functional theory},
author = {Sissay, Adonay and Abanador, Paul and Mauger, François and Gaarde, Mette and Schafer, Kenneth J. and Lopata, Kenneth},
abstractNote = {Strongfield ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionizationtriggered charge migration. Modeling ionization dynamics in molecular systems from firstprinciples can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require nonperturbative timedependent electronic structure methods. In this paper, we develop a timedependent density functional theory approach which uses a Gaussiantype orbital (GTO) basis set to capture strongfield ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a timedependent laser potential and a spatial nonHermitian complex absorbing potential which is projected onto an atomcentered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned rangeseparated functional LCPBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angledependent ionization), and the results are shown to quantitatively agree with timedependent Schrödinger equation and strongfield approximation calculations. In conclusion, this tuned DFT with GTO method opens the door to predictive allelectron timedependent density functional theory simulations of ionization and ionizationtriggered dynamics in molecular systems using tuned rangeseparated hybrid functionals.},
doi = {10.1063/1.4961731},
journal = {Journal of Chemical Physics},
number = 9,
volume = 145,
place = {United States},
year = {2016},
month = {9}
}