# Overview of input options¶

Below is the overview for all the keys in the VibrationalAnalysis block:

VibrationalAnalysis
AbsorptionSpectrum
AbsorptionRange float_list
FrequencyGridPoints integer
LineWidth float
SpectrumOffset [absolute | relative]
End
Displacement float
ExcitationSettings
EnergyInline float
ExcitationFile string
ExcitationInputFormat [File | Inline]
GradientInline # Non-standard block. See details.
...
End
Singlet # Non-standard block. See details.
...
End
Triplet # Non-standard block. See details.
...
End
End
ModeTracking
HessianGuess [Unit | File | UFF]
HessianInline # Non-standard block. See details.
...
End
HessianPath string
ToleranceForBasis float
ToleranceForNorm float
ToleranceForResidual float
ToleranceForSpectrum float
TrackingMethod [...]
UpdateMethod [JD | D | I]
End
NormalModes
MassWeightInlineMode [True | False]
ModeFile string
ModeInline # Non-standard block. See details.
...
End
ModeInputFormat [File | Inline | Hessian]
ModeSelect
DisplacementBound float
FreqAndIRRange float_list
FreqRange float_list
Full [True | False]
HighFreq integer
HighIR integer
IRRange float_list
ImFreq [True | False]
LargestDisplacement integer
LowFreq integer
LowFreqNoIm integer
LowIR integer
ModeNumber integer_list
End
ScanModes [True | False]
End
ResonanceRaman
IncidentFrequency float
RamanOrder integer
RamanRange float_list
End
Type [ModeScanning | ModeTracking | ModeRefinement | VibronicStructure | VibronicStructureTracking | VibronicStructureRefinement | ResonanceRaman]
VSTRestartFile string
End

VibrationalAnalysis
Type: Block Input data for all vibrational analysis utilities in the AMS driver.
AbsorptionSpectrum
Type: Block Settings related to the integration of the spectrum for vibronic tasks.
AbsorptionRange
Type: Float List [-200.0, 4000.0] cm-1 True Specifies frequency range of the vibronic absorption spectrum to compute. (2 numbers: an upper and a lower bound.)
FrequencyGridPoints
Type: Integer 400 Number of grid points to use for the spectrum
LineWidth
Type: Float 200.0 cm-1 Lorentzian line-width.
SpectrumOffset
Type: Multiple Choice relative [absolute, relative] Specifies whether provided frequency range are absolute frequencies or frequencies relative to computed 0-0 excitation energy.
Displacement
Type: Float Step size for finite difference calculations.
ExcitationSettings
Type: Block Block that contains settings related to the excitation for vibronic tasks.
EnergyInline
Type: Float hartree Vertical excitation energy, used when [ExcitationInfo] = [Inline].
ExcitationFile
Type: String Path to a .rkf/.t21 file containing the excited state information (gradients, transition dipoles and energies).
ExcitationInputFormat
Type: Multiple Choice File [File, Inline] Select how the application should retrieve the excited state information (energy, gradient).
GradientInline
Type: Non-standard block Excited state gradient at ground state equilibrium geometry, used when [ExcitationInfo] = [Inline].
Singlet
Type: Non-standard block Symmetry labels + integer indices of desired singlet transitions (VG-FC absorption spectra support only 1 at a time)
Triplet
Type: Non-standard block Symmetry labels + integer indices of desired triplet transitions (VG-FC absorption spectra support only 1 at a time)
ModeTracking
Type: Block Input data for Mode Tracking.
HessianGuess
Type: Multiple Choice UFF [Unit, File, UFF] Guess Hessian Sets how to obtain the guess for the Hessian used in the preconditioner (if one is to be used).
HessianInline
Type: Non-standard block Initial guess for the (non-mass-weighted) Hessian in a 3N x 3N block, used when [HessianGuess] = [Inline].
HessianPath
Type: String Path to a .rkf file containing the initial guess for the Hessian, used when [HessianGuess] = [File].
ToleranceForBasis
Type: Float 0.0001 Convergence tolerance for the contribution of the newest basis vector to the tracked mode.
ToleranceForNorm
Type: Float 0.0005 Convergence tolerance for residual RMS value.
ToleranceForResidual
Type: Float 0.0005 Convergence tolerance for the maximum component of the residual vector.
ToleranceForSpectrum
Type: Float 0.01 Convergence tolerance for the spectrum in Vibronic Structure Tracking.
TrackingMethod
Type: Multiple Choice OverlapInitial [OverlapInitial, DifferenceInitial, FreqInitial, IRInitial, OverlapPrevious, DifferencePrevious, FreqPrevious, IRPrevious, HighestFreq, HighestIR, LowestFreq, LowestResidual] Set the tracking method that will be used. Vibronic Structure Tracking uses Largest Displacement.
UpdateMethod
Type: Multiple Choice [JD, D, I] Chooses the method for expanding the Krylov subspace: (I) No preconditioner (VST default), (D) Davidson or (JD) vdVorst-Sleijpen variant of Jacobi-Davidson (Mode tracking default).
NormalModes
Type: Block All input related to processing of normal modes. Not available for vibronic structure tracking (as no modes are required there).
MassWeightInlineMode
Type: Bool True MODE TRACKING ONLY: The supplied modes must be mass-weighted. This tells the program to mass-weight the supplied modes in case this has not yet been done. (True means the supplied modes will be mass-weighted by the program, e.g. the supplied modes are non-mass-weighted.)
ModeFile
Type: String Path to a .rkf or .t21 file containing the modes which are to be scanned. Which modes will be scanned is selected using the criteria from the [ModeSelect] block.) This key is optional for Resonance Raman and Vibronic Structure. These methods can also calculate the modes using the engine.
ModeInline
Type: Non-standard block True MODE TRACKING ONLY: Coordinates of the mode which will be tracked in a N x 3 block (same as for atoms), used when [ModeInputFormat] = [Inline]. Rows must be ordered in the same way as in the [System%Atoms] block. Mode Tracking only.
ModeInputFormat
Type: Multiple Choice File [File, Inline, Hessian] Tracked mode source Set how the initial guesses for the modes are supplied. Only mode tracking supports the Inline and Hessian options.
ModeSelect
Type: Block Pick which modes to read from those from file.
DisplacementBound
Type: Float Vibronic Structure (Refinement), Resonance Raman: Select all modes with a dimensionless oscillator displacement greater than the specified value.
FreqAndIRRange
Type: Float List cm-1 and km/mol True Specifies a combined frequency and IR intensity range within which all modes will be selected. (First 2 numbers are the frequency range, last 2 numbers are the IR intensity range.)
FreqRange
Type: Float List cm-1 True Specifies a frequency range within which all modes will be selected. (2 numbers: a upper and a lower bound.)
Full
Type: Bool False All modes Select all modes.
HighFreq
Type: Integer # High frequencies Select the N modes with the highest frequencies.
HighIR
Type: Integer # High IR Select the N modes with the largest IR intensities.
IRRange
Type: Float List km/mol True Specifies an IR intensity range within which all modes will be selected. (2 numbers: a upper and a lower bound.)
ImFreq
Type: Bool False All imaginary frequencies Select all modes with imaginary frequencies.
LargestDisplacement
Type: Integer Vibronic Structure (Refinement), Resonance Raman: Select the N modes with the largest VG-FC displacement.
LowFreq
Type: Integer # Low frequencies Select the N modes with the lowest frequencies. (Includes imaginary modes which are recorded with negative frequencies.)
LowFreqNoIm
Type: Integer # Low positive frequencies Select the N modes with the lowest non-negative frequencies. (Imaginary modes have negative frequencies and are thus omitted here.)
LowIR
Type: Integer # Low IR Select the N modes with the smallest IR intensities.
ModeNumber
Type: Integer List Mode numbers Indices of the modes to select.
ScanModes
Type: Bool False Scan after refining Supported by: Mode Tracking, Mode Refinement, Vibronic Structure Refinement: If enabled an additional displacement will be performed along the new modes at the end of the calculation to obtain refined frequencies and IR intensities. Equivalent to running the output file of the mode tracking calculation through the AMS ModeScanning task.
ResonanceRaman
Type: Block Block that contains settings for the calculation of Resonance Raman calculations
IncidentFrequency
Type: Float cm-1 Frequency of incident light. Also used to determine most important excitation in case more than one is provided.
LifeTime
Type: Float 0.00045 hartree Lifetime of Raman excited state.
RamanOrder
Type: Integer 2 Order up to which to compute Raman transitions
RamanRange
Type: Float List [0.0, 2000.0] cm-1 True Specifies frequency range of the Raman spectrum to compute. (2 numbers: a upper and a lower bound.)
Type
Type: Multiple Choice [ModeScanning, ModeTracking, ModeRefinement, VibronicStructure, VibronicStructureTracking, VibronicStructureRefinement, ResonanceRaman] Specifies the type of vibrational analysis that should be performed
VSTRestartFile
Type: String Path to a .rkf file containing restart information for VST.