Welcome to Duo’s documentation!¶
Contents:
- Duo
- Running and Compiling Duo
- Duo Input file: general structure
- Computing energy levels
- Computing spectra (intensities and line lists)
- Contractions and vibrational basis set
- Specification of curves and couplings (Duo objects)
potentialabinitioLxandL+spin-orbitandspin-orbit-xspin-spinspin-rotbob-rotbob-vibdiabatic- Non-adiabatic coupling:
NAC lambda-opq,lambda-p2q, andlambda-qL2dipoleanddipole-xquadrupoleMAGNETICMAGNETROT- Keywords used in the specification of objects
- Cartesian or tensorial representation
- Duo Functions
- Potential energy functions
- Extended Morse Oscillator
EMO - Morse Long-Range (MLR) function
MLR - Coxon and Hajigeorgiou’s MLR3 Morse Long-Range with Douketis Damping
MLR3 - Hajigeorgiou and Le Roy’s MLJ Morse/Lennard-Jones oscillator
MLJ - Diagonal BO-breakdown functions (rotationless)
BOB-Z-M-SWITCH,BOB_Z_M_SWITCH - Potential function
Marquardt - Morse oscillator
Morse Morse_dampModified-MorsePolynomial- Simons, Parr and Finlan
SPF - Murrell-Sorbie
M-S Chebyshevirreg_chebyshev_DMCCOSH-POLYREPULSIVEREPULSIVE_EXPPOLYNOM_DECAY_24POLYNOM_DECAY_DAMPCO_X_UBOS
- Extended Morse Oscillator
- Coupled functions with adiabatic avoided crossings
- Other functional forms
- Surkus-polynomial expansion
Surkus(BobLeroy) Surkus-damp(aliasBobLeroy_damp)- Coxon-type Surkus-polynomial expansion
BobCoxon POLYNOM_DIMENSIONLESSPADE_GOODISMAN2(PADE2)MEDVEDEV_SING2(SING2)IRREG_CHEBYSHEV_2024- Mass-dependent BOB non-adiabatic Surkus-polynomial expansion
BOBNA SIGMOIDfunctionEMO-SWITCHfunction
- Surkus-polynomial expansion
- Diabatic/non-adiabatic couplings
- Implementation guide
- Glossary
- Potential energy functions
- Duo fitting
- Defining the grid
- Checkpointing (wavefunctions, moments, and reduced density)
- Overview of the
checkpointblock - What gets written: checkpoint files
- Writing checkpoints for later intensity work
- Reading checkpoints to compute intensities (no recomputation)
- Recomputing moment matrix elements with new dipole curves (
dipole calc) - Controlling the format of
*_vectors.chk(binary vs ascii) - Structure of
<prefix>_vectors.chk(eigenvector checkpoint file) - Example: structure of
*_values.chk(eigenvalue checkpoint file) - Reduced density calculations
- Notes on terminology and legacy keywords
- Keywords
- Overview of the
- Treating unbound states
- Omega representation
- Duo keywords
- Nuclear hyperfine structure
- How to cite Duo
- MIT License
ranges
representation
and Recent news¶
09.04.2026: The new funcitonality Omega-representation has been added currently only for spin-orbit and spin.
march 2026: Unbound spectra calculations are now possible down from bound to free (unbound lower).
05.01.2026: The checkpoint functionality now allows using stored eigenfunctions directly in intensity calculations thus bypassing the solution of the Schrödinger system. This functionality also includes saving/reading/computing the transition dipole/quadrupole matrix elements (external). The format of the eigenvectors checkpoint is now binary. There is a new eigenvalues .chk file. As a new feature, it can potentially contain bugs (most likely).