ReSpect (Relativitic Spectroscopy) is a free, parallel computational chemistry program for relativistic calculations of spectroscopic properties of atoms and molecules. Since the underlying theory combines a fully relativistic (four-component) Dirac approach with all-electron Kohn-Sham density functional theory, ReSpect offers unique capabilities, both in terms of accuracy and efficiency, to study the spectroscopic parameters of molecules with heavier atoms such as transition metals, lanthanoids or actinoids. The program also provides in-built all-electron basis sets of Gaussian-Type Orbitals (GTOs) suitable for relativistic calculations of elements across the periodic table (Z=1-118).


Model Hamiltonians

  • Kohn-Sham (KS) - non-relativistic one-component
  • Hartree-Fock (HF) - non-relativistic one-component
  • Exact two-component (X2C) - relativistic two-component
  • modified Dirac-Kohn-Sham (mDKS) - relativistic four-component
  • modified Dirac-Hartree-Fock (mDHF) - relativistic four-component
  • all model Hamiltonians support Kramers restricted and unrestricted formalism

DFT Exchange-Correlation Functionals

  • pure DFT functionals of LDA & GGA type
  • hybrid DFT functionals
  • adaptive numerical integration grid
  • non-collinear formulation of all DFT functionals
  • analytical kernels for all DFT functionals

Spectroscopic properties

  • Nuclear Magnetic Resonance (NMR) Spectroscopy
  • Electron Paramagnetic/Spin Resonance (EPR/ESR) Spectroscopy
  • Nuclear Spin-Rotation Constant
  • UV/Vis and X-ray Absorption Spectroscopy
  • Electric Circular Dichroism (ECD)
  • Nuclear Quadrupole Interactions (EFG)
  • Mössbauer Spectroscopy

Performance and Parallelization

  • Vectorized and parallel integral library (InteRest)
  • OpenMP and MPI parallel two-electron Fock library
  • Efficient and parallel XC numerical integration
  • Linear-scaling technology (integral screening, LinK)
  • RI-J technology for the Coulomb two-electron contribution

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Our Contacts

Hylleraas Centre
Department of Chemistry
UiT The Arctic University of Norway
Tromsø, NO-9037 Norway