Transient (Pump-Probe) Absorption Spectroscopy with RT-TDDFT

Documentation on the molecular calculation of transient (pump-probe) absorption spectra (TAS) using relativistic real-time quantum electron dynamics. The pump-probe technique can be described by a sample being photo-excited by a light source (pump pulse), whereby a second light source (probe pulse) is measured for changes in absorption as a function of wavelength and time. The methodology implemented in ReSpect combines the real-time time-dependent density functional theory (RT-TDDFT) with the 1C, (e)amfX2C or 4C Hamiltonian and can be applied to closed-shell molecular systems.

Tutorial

SCF Keywords

TDSCF Keywords

Feature List

Wave function models

  • Kramers restricted Hartree-Fock or Kohn-Sham determinant for closed-shell singlets

Hamiltonians

  • non-relativistic one-component (1c)
  • relativistic four-component (4c) Dirac-Coulomb
  • relativistic two-component (2c) involving 1eX2C, amfX2C, eamfX2C or mmfX2C Hamiltonian models
  • scalable speed of light

DFT non-collinear functionals

  • local (SVWN5)
  • GGA (PBE,BLYP,KT2,BP86,PP86)
  • hybrid (PBE0,B3LYP)
  • range-separated (LC-SVWN5,LC-BLYP,CAM-B3LYP)

Nuclear charge distribution models

  • point
  • finite Gaussian-type

Integral evaluation techniques

  • analytic with an in-built restricted kinetic balanced (RKB) condition for the small-component
  • resolution-of-the-identity for the Coulomb two-electron term (RI-J)
  • one-center approximation for the SSSS-type electron repulsion integrals

Equation-of-motion solvers

  • Magnus propagator with a self-consistent extrapolation-interpolation scheme

External electric field models

  • Gaussian-type impulse
  • analytical representation of the Dirac delta impulse
  • monochromatic cosine wave with/without a linear envelope

Additional features

  • selective perturbation/response
  • molecular orbital analysis of spectroscopic transitions
  • parallel execution on shared-memory parallel architectures (SMPs)

Related Publications

T. Moitra, L. Konecny, M. Kadek, A. Rubio, and M. Repisky
Accurate Relativistic Real-Time Time-Dependent Density Functional Theory for Valence and Core Attosecond Transient Absorption Spectroscopy
J. Phys. Chem. Lett. 14, 1714–1724 (2023)

M. Repisky, L. Konecny, M. Kadek, S. Komorovsky, O. L. Malkin, V. G. Malkin, and K. Ruud
Excitation energies from real-time propagation of the four-component Dirac-Kohn-Sham equation
J. Chem. Theory Comput. 11, 980–991 (2015)

L. Konecny, M. Kadek, S. Komorovsky, O. L. Malkina, K. Ruud, and M. Repisky
Acceleration of relativistic electron dynamics by means of X2C transformation: application to the calculation of nonlinear optical properties
J. Chem. Theory Comput. 12, 5823–5833 (2016)

Book Chapter

M. Kadek, L. Konecny, and M. Repisky
Relativistic Real-Time Methods
In: Yanez, Manuel and Boyd, Russell J. (eds.) Comprehensive Computational Chemistry, Vol. 3, Elsevier , 200–228 (2024)

Program Reference

M. Repisky, S. Komorovsky, M. Kadek, L. Konecny, U. Ekstrom, E. Malkin,
M. Kaupp, K. Ruud, O. L. Malkina, and V. G. Malkin
ReSpect: Relativistic spectroscopy DFT program package
J. Chem. Phys. 152, 184101 (2020)

Additional contributions from
R. Bast (AutoCMake), R. Di Remigio (PCMSolver), I. Malkin-Ondik (DKH2), and S. Knecht (MPI parallelization)

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Our Contacts

Hylleraas Centre
Department of Chemistry
UiT The Arctic University of Norway
Tromsø, NO-9037 Norway
Email: info@respectprogram.eu