Software Packages for Broadband High-Resolution Spectroscopy
This page was, according to the WayBackMachine, created in 2007.  Quite a few changes have taken place since then.  New packages have been added and package availability was checked in Jan 2023.  Greyed out tables indicate discontinued availability.
        Experimental techniques of contemporary high-resolution spectroscopy can result in a deluge of experimental data in the form of multi-million point length spectra containing well over 100000 lines. The associated data reduction problem is being actively tackled in several research groups and below is a brief summary and starting links to the various approaches that have been developed.

        All packages are for the Windows world and all are freely available from the authors, either by a straightforward download or on request. In most cases emphasis has been placed on being able to carry out graphical analysis based on Looms-Wood type plots of recorded spectra. In this respect the interactive Loomis-Wood program developed in the Winnewisser laboratory in Giessen, Germany was of pioneering importance.

        The current packages can be subdivided into several groups. The first group consists of those that stem from applications in rotational spectroscopy:

AABS, CAAARS, DAPPERS, JB95, LLWP, SMAP (in alphabetical order)

        A second group of packages results from analysis of vibration-rotation spectra in the infrared:

ATIRS, Giessen Loomis-Wood, INFIA, Loomis-Wood Add-In, LWW, PGOPHER, VMS-ROT (also in alphabetical order)

        Most of these packages, especially those based on the SPFIT/SPCAT engine for fitting and prediction, should in principle be able to deal with both pure-rotation, rotation-vibration and vibronic spectra.

Package: AABS = Assignment and Analysis of Broadband Spectra
Author: Zbigniew KISIEL
Institution: Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
Download: All files directly downloadable from the webpage
Examples: Yes - a sample project for lactic acid and mini-tutorial are on the webpage

        The impulse to write this package came from the need to deal with FASSST spectra on relatively low-end computers. The package turned out to be very useful for the analysis also of the MMW rotational spectra recorded in our Warsaw laboratory, of supersonic expansion FTMW spectra, and of rotation-vibration spectra from several synchrotron radiation based FTIR spectrometers.

        AABS can use several different packages for fitting/prediction.  The input/output of two packages can be used directly, and these are:
        ASFIT/ASROT - straightforward asymmetric rotor treatment up to decadic terms,
        SPFIT/SPCAT - general Hamiltonian for up to six quantum numbers.
Two additional packages can be used by means of available input/output reformatting programs:
        ERHAM - Effective Rotational HAMiltonian fit,
        RAM36 - Rho Axis Method internal rotor fit.

        The AABS package has been described in:

  • Z.Kisiel, L.Pszczolkowski, I.R.Medvedev, M.Winnewisser, F.C.De Lucia, E.Herbst, J.Mol.Spectrosc. 233,231-243(2005)

        A list of applications is in Table 2 of:

  • Z.Kisiel, L.Pszczolkowski, B.J.Drouin, C.S.Brauer, S.Yu, J.C.Pearson, I.R.Medvedev, S.Fortman, C.Neese,
    J.Mol.Spectrosc. 280,134-144(2012)


Package: CAAARS = Computer Aided Assignment of Asymmetric  Rotor Spectra
Author: Ivan MEDVEDEV
Institution: Department of Physics, The Ohio State University, Columbus, Ohio, USA
Website: Vanished, but the author I.R.Medvedev is still in Academia, so might be contacted for package availability.

The package needs the commercially available Igor Pro program for operation.


        This originated as an in-house package to deal with the FASSST spectra recorded at Ohio State. The package has been used intensively in many different analyses by the OSU Microwave Group.  It has been designed to use SPCAT/SPFIT, and there are rumours that it also works with Peter Groner's ERHAM.

        CAAARS is actually an add-on to the commercial IGOR PRO program, so you have to buy that first.  If you are serious about processing very extended spectra then the purchase of IGOR PRO might be a good step anyway, as it is a very efficient, no-nonsense, program for dealing with very large datasets.

       The CAAARS package has been described in:

  • I.R.Medvedev, M.Winnewisser, B.P.Winnewisser, F.C.De Lucia, E.Herbst, J.Mol.Struct. 742, 229-236 (2005)


Package: DAPPERS = Data Analysis Package for Productive and Enthusiastic Rotational  Spectroscopists
Author: Nathan LOVE
Institution: Department of Chemistry, University of Minnesota, Minneapolis, USA
Download: Installation package (200 MB zip file) available at the link on the bottom of the program website.

       The DAPPERS package has been introduced and described in:

  • N.Love, A.K.Huff, K.R.Leopold, "A new program for the assignment and fitting of dense rotational spectra based on spectral progressions: Application to the microwave spectrum of pivalic anhydride", J.Mol.Spectrosc. 370, 111294:1-7 (2020)


Package: JB95 Spectral Fitting Program
Author: David F. PLUSQUELLIC
Institution: Optical Technology Division, National Institute of Standards and Technology, Gaithersburg, USA
Download: 32-bit and 64-bit versions are available in downloadable ZIP archives.  Links to the documentation are on the lower-right hand side of the web page.
Examples: Not available, although the documentation is based upon a discussion of a sample project in the directory 1fnMW. The contents of this directory does not seem to be available on the web but perhaps the author will provide it if requested.

        This package was created to deal with the results of the broadband spectra acquired by the NIST auto-scanning FTMW spectrometer.  The package consists of the main
jb95 GUI module, and three ancillary programs:

iar95 - calculation of rotational spectra
quad95 - fitting of nuclear quadrupole structure (single nucleus to 2nd order perturbation theory)
ga95 - fitting of constants using the genetic algorithm method


Package: LLWP = (Luis?) Loomis-Wood Plots
Author: Luis BONAH
Institution: I. Physikalisches Institut Universität zu Köln, Köln, Germany
Download: Available as Python code and a Windows installer.
Examples: Sample data available on the download page.

       The LLWP package has been introduced and described in:

  • L.Bonah, O.Zingsheim, H.S.P. Müller, J-C.Guillemin, F.Lewen, S.Schlemmer, "LLWP —A new Loomis-Wood software at the example of Acetone-13C1", J.Mol.Spectrosc. 388, 111674:1-10 (2022)


Package: SMAP SubMillimeter Analysis Program
Author: Brian DROUIN ?
Institution: Jet Propulsion Laboratory, Pasadena, California, USA
Download: Installation package directly downloadable, but no help system and no documentation.
Examples: Not available.

        This is an in-house package for dealing with spectra recorded at jpl and promises to do a lot once you find out how to use it. Spectra can be in several different formats, among them simple ASCII two-column frequency,intensity format (called .dat in the input options).


Package: ATIRS = Asymmetric Top InfraRed Spectra
Author: Nicola TASINATO et al.
Institution: Dipartimento di Chimica Fisica, Università Ca' Foscari di Venezia, Venezia, Italy
Download: This package is no longer available, but it has been described in Journal of Molecular Spectroscopy, Volume 243, Issue 2, p. 148-154, DOI: 10.1016/j.jms.2007.02.016

        This package consists of three modules:

VLW - Visual Loomis Wood
VCALPGM - Visual CALPGM, which is a graphical front-end for Pickett's SPFIT/SPCAT
VSS - Visual Spectra Simulator

        The programs are written in Visual Basic 2005, hence the requirement for Microsoft .NET Framework 2.0. Note that you typically will have to download the: "Microsoft .NET Framework Version 2.0 Redistributable Package (x86)" 22.4 Mb and not, for example, the ".NET Compact Framework 2.0 Service Pack 1 Redistributable" which does not work, even though it implies that it is a Service Pack to the first package.

        The package was first presented at the PRAHA2006 conference.


Package: Giessen Loomis-Wood
Author: J.Reinstadler (earlier Turbo-Pacal 3.0 version), J.Behrend (later Turbo-Pascal 4.0 version)
Institution: Physikalisch-Chemisches Institut der Justus-Liebig-Universitiit, Giessen, Germany
I. Physikalisches Institut der Universitiit zu Koln, Koln, Germany
Website: Predates the internet website system so originally available "on request from the authors"
Download: Subversions are still around in software archives of those associated with the Giessen group, but require a suitable MS-DOS emulator for operation.

        The name above is a colloquially used loose description of several seminal programs developed in the Giessen laboratory, jointly with Cologne laboratory (both in Germany).   These predate graphical operating systems but used interactive MS-DOS based graphics for operation.  A still very useful description of the algorithm and features
has been published in:

  • B.P.Winnewisser, J.Reinstadler, K.M.T.Yamada, J.Behrend, "Interactive Loomis-Wood Assignment Programs", J.Mol.Spectrosc. 136, 12-16 (1989).


Package: INFIA = Program for Rotational Analysis of Linear Molecule Spectra
Author: Robert BROTHERUS.
Institution: Laboratory of Physical Chemistry, University of Helsinki, Finland.
Website: Vanished
Examples: There used to be three different projects: for CO, DCCBr, and CH3Br (all included in the distribution package)

        This was the first published Windows program with Loomis-Wood graphical assignment capabilities. Developed for analysis of multistate linear-rotor vibration-rotation spectra, and can deal with the various possible resonances.

        A comprehensive description of INFIA has been published in:

  • R.Brotherus, J.Comput.Chem. 20, 610-622 (1999)


Package: Loomis-Wood Add-In
Author: Christopher F. NEESE
Institution: Department of Physics, University of Chicago, Chicago, USA
Download: Package documentation and tutorial are available on the web page, and the package itself can be downloaded after typing in your email.

You also need to get the commercially available Igor Pro program.

2023 update: website as stated above has vanished

Examples: Yes - a sample project for ethylene is included in the distribution package.

        This package, as the name implies, is in the form of a set of routines for the versatile IGOR PRO program for graphical analysis of data. It seems to be tailored to be used in analysis of spectra of linear molecules. Considerable effort has gone into documentation of this package. There is a web-based manual, a tutorial, as well as a help file added to the Igor Pro help system. The tutorial ends with a very apt paragraph, which is applicable to all packages compared on this page:

        ... Remember, the Loomis-Wood Add-In is just a tool. At all times, you need to understand what you are doing to get meaningful results. The add-in is not a tool to allow novices to assign complicated spectra. The add-in is a tool to help spectroscopists assign spectra faster with fewer mistakes, since the add-in minimizes the need to manually assign and manipulate line-lists. In particular, do not neglect to examine the actual spectrum to make sure your assignments make sense.

The package was presented at the 2005 OSU Symposium.

Package: LWW = Loomis Wood for Windows
Author: Wieslaw LODYGA et al.
Institution: Department of Chemistry, Adam Mickiewicz University, Poznan, Poland
Download: Documentation available on the website, package is sent by the authors on request.
Examples: None available, although the authors provided a sample project for LWW when requested.

        This program comes in two flavours:

LWW - for symmetric top molecules
LWWa - for asymmetric top molecules (just announced)

        The format of input and output files is configurable so it is possible to combine the programs with different fitting/prediction packages. The default fitting program for LWW is Petr Pracna's SimFit, and the quantisation is J,K,l,vLWWa is stated to work with SPFIT/SPCAT, using J,Ka,Kc,v quantisation.

        The package was first presented at the PRAHA2006 conference.


Package: PGOPHER, a program for simulating rotational structure
Author: Colin WESTERN
Institution: School of Chemistry, University of Bristol, UK
Download: Installation package directly downloadable, help system in the program, extensive online documentation on the author's website.
Examples: Sample data files , as well as interactive samples are available on the website

        The program promises not only to simulate, but also to fit rotational structure in vibrational of electronic spectra of linear, symmetric and asymmetric top molecules. Interstate interactions can be accounted for, and it appears that pure rotational spectra can also be dealt with. Frequency calibration of

        The package was presented in communication TH12 at the 62nd OSU Symposium, 2007. PGOPHER has also been described in the following journal publications:

  • C.M.Western, "PGOPHER: A program for simulating rotational, vibrational and electronic spectra", J.Quant.Spectrosc.Radiat.Transf. 186, 221-242 (2017)
  • C.M.Western and B.E.Billinghurst, "Automatic assignment and fitting of spectra with PGOPHER", Phys.Chem.Chem.Phys. 19, 10222-10226 (2017)

        Regrettably the author is now deceased, although the program website (as of 2023) is active.

Package:VMS-ROT, a module for dealing with rotational spectra as part of the VMS package
Author: Daniele LICARI et al.
Institution: Scuola Normale Superiore, Pisa, Italy
Download:2017: By request, under the "Download" tab on the website. Requires Java for operation.
2023: The website link provided above is no longer active.
Examples:In the form of several tutorial movies.

        This module is one of the VMS Draw tools being part of the Virtual Multi-spectral Spectrometer package under development in Pisa. 

        It was introduced in D.Licari, N.Tasinato, L.Spada, C.Puzzarini, V.Barone, J.Chem. Theory Comput. 13, 4382-4396 (2017).


Go to the PROSPE webpage

Go to the ROTLINKS webpage