Version 1.64 available, VCD/IR supported since Version 1.63

SpecDis is a handy tool to process the results of quantum-chemical ECD/UV, ORD, or VCD/IR calculations. It supports diverse software packages like ORCA, Gaussian03, Gaussian09, Turbomole (escf, ricc2),  NWChem, ADF, DALTON, or Grimme´s sTDA software (simplified TDDFT).

SpecDis can visualize the computational results and has several possibilities to further process the spectra. Some of the features of SpecDis are:

  • compare calculated ECD/UV, ORD, or VCD/IR spectra directly with experimental data (up to 5 curves)
  • Gauss and Lorentz curve generation
  • provide an enantiomeric ECD/VCD spectrum
  • applying a "UV shift" or a scaling factor for VCD/IR
  • arithmetic or Boltzmann weighted summation of spectra
  • determining a similarity factor
  • plot spectra with gnuplot in a "what you see is what you get" manner
  • export spectral curves as *.xy files that can be processed with other software like Excel or Origin
  • plot UV and CD traces of HPLC runs
  • automatic extraction of heats of formation and spectral data from output files
  • preliminary handling of ORD calculations with Gaussian03 and Gaussian09
  • Boltzmann weighting of ORD values
  • Similarity Factors for ECD/UV and VCD/IR spectra


We are grateful to Dr. Pescitelli (University of Pisa; Italy) for helpfull discussions and beta testing of SpecDis.

System Requirements

SpecDis is tested under Windows 7 SP1 and Suse Linux Enterprise Server 11.3, Windows 8 has not been fully tested but the Win7 version  should work correctly. For Windows 7  (and 8) Specdis has to be installed on a partioned disk other than c:\, otherwise one might get administrator-right problems.Win XP and Vista are no longer supported!

The Interface to Gnuplot is tested up to version 5.0, png plotting will work with gnuplot 4.6 and higher only!

If you have any questions or suggestions feel free to send an email to .




You can freely download this software, but if you use it for publications please cite SpecDis as:

T. Bruhn, A. Schaumlöffel, Y. Hemberger, SpecDis version 1.63, University of Wuerzburg, Germany, 2015.


SpecDis: Quantifying the Comparison of Calculated and Experimental Electronic Circular Dichroism Spectra, T. Bruhn, A. Schaumlöffel, Y. Hemberger, G. Bringmann, Chirality 2013, 25, 243–249.

SpecDis is offered as-is, without any warranty!

Download SpecDis together with a preliminary manual  as a zip archive from the following links:

Windows 7:  Initiates file downloadSpecDis164

Linux GTK2, 64Bit: Initiates file downloadSpecDis164

After unzipping under Linux the SpecDis binary has to be made executable by using:

chmod ugo+x  SpecDis164


Win XP is no longer supported, an older version can be downloaded here:

Windows XP, 32Bit, version 1.61!: Initiates file


For a discussion on suited methods for the calculation of ECD by TDDFT calculations have a look at:

Good Computational Practice in the Assignment of Absolute Configurations by TDDFT Calculations of ECD Spectra, G. Pescitelli*, T. Bruhn*, Chirality 2016, published online, DOI:10.1002/chir.22600.

Changes since version 1.63

SpecDis now reads the results of simplified TDDFT calculations (the tda.dat file) done with the sTDA executable provided by the Grimme group, University of Bonn.



Major changes since 1.62

  • SpecDis shows experimental and G09-calculated VCD and IR spectra
    Summation of VCD and IR spectra added
    Calculated VCD and IR spectra can be exported as bil and xy files
    automatic extraction of VCD and IR data from several log/out files
  • corrected a bug with scaling in 3D chromatograms, before the first chromatogram was not scaled at all
  • corrected a bug in the heat and spectra-extract algorithms that prevented extraction of energies or spectra on Linux systems
  • removed a bug in the similarity algorithm that sometimes gave the 'invalid floating point operation' error
  • automatic extraction of ECD/UV now reads excitation in a range of 100-4000nm (before only 100-1100nm)
  • added the possibility to select a separate directory for heat files in the boltzmann weighting tool
  • number of xtics increased to 10, numbers at the x axis should be less weird now
  • units are given now in bil files (VCD/IR and ECD/UV)
  • added a plausibility check for wavelength, shift, wavenumber, and scaling factor values so that SpecDis produces less error messages, senseless values (e.g. x1 larger than x2, non numerical inputs) will be ignored now  
  • automatic extraction extended, one can choose now if the folder or subfolder is searched for data
  • weighting factors for ORD are shown in the summation tool
  • autoscaling checkbox added for ORD, now the ORD data of a second file can be shown in the same scale as that of the first file
  • plotting routines for eps were slightly changed to fit to gnuplot version 5.x
  • corrected a bug in ECD plotting, the bar spectra of an enantiomer is plottable now with Gnuplot (before the normal CD was plotted instead)



Changes since Version 1.61

  • Experimental ORD spectra with more than 400 datapopints are readable now
  • Checking if all curves have different names has been corrected for long names
  • Import of NWChem files has been implemented, this is still a beta version and we need feedback from the users, as we do not use NWChem. If it works bugfree we will implement an 'automatic extraction', too
  • Increased the number of possible data points for experimental UV and CD spectra to 10000
  • Increased the maximum lambda value to 4000 nm
  • Loading routines for g09 has been improved, SpecDis now reads the velocity results from Rev. D.01
  • Fixed a bug that sometimes prevented reading of ricc2-files
  • Length and velocity results of a DALTON 2013.2 calculation are readable now (Final results from ABACUS)
  • The legend of the y axis of calculated CD spectra is now correctly per M per cm in the gnuplot settings, the sgs units are only valid for bar spectra
  • Second y axis for CD spectra has been changed, if 'bar spectra' is activated, all Curves are plotted against the left y axis and they are scaled to the spectrum with the highest intensity, only the bar spectrum is plotted against the right axis. If bar spectra are deactivated all calculated spectra are plotted against the right axis and no scaling is applied
  • Corrected a bug in the calculations of Lorentz curves, before the factor gamma was multiplied to often, however, this had only a small influence on the absolute values.
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