A program for molecular data visualization, molecular construction, and thermodynamic calculations

(Last update: 09.10.2015)

Moltran is a program for inspection of results after quantum chemical calculations performed with different quantum chemical packages including Gaussian, GAMESS, Priroda, CFOUR and others. It allows editing the molecular structures working as a molecular builder. During the molecular editing, you can save or retrieve the molecular fragments to a database and use them later to create more complicated structures. A special feature of MOLTRAN is a possibility to perform various thermodynamical calculations (with a broad variation of model parameters) and taking into account the internal rotations if they are present in the molecule. Have a look at the Moltran screenshots (sample data files creating the screenshots can also be found here).

Moltran Manual

Thermodynamic calculations with Moltran

Download Moltran for Win7/Win8 — MOLTRAN v.2.5 (build 2155) for Windows7 / Windows8 with graphic interface. Gaussian09, GAMESS-US, PC GAMESS, Priroda8, and CFOUR (partially) formats are supported. Note: Due to the extra security rules of Windows7/8 applied to «c:\Program Files(x86)» directory, it is recommended to install the program to other folder (say, c:\Moltran). Otherwise, problems with fragments database can appear.

Download Moltran for WinXP — MOLTRAN v.2.5 (build 1680) for WindowsXP with graphic interface (MoltranSetup.exe, zipped to avoid the server restrictions, Short manual and UnInstaller are included). Stable on Windows 2000, XP, Vista. Gaussian09 format is now supported.

Moltran for Linux — experimental release of build 1373 w/o graphics interface — only for TD calculations. Compiled with Intel Fortran 10.1 under OpenSuse 10.3 (Intel+AMD platforms). Installation instruction (install_unix.txt) inside the zip-archive (

New features in the current version

  • Automatic Recognition of Internal Rotations (ARIR)
  • Improved thermodynamic calculations with internal rotations
  • Automatic recognition of symmetry group and rotation symmetry number
  • Semiempirical optimizations
  • Improved operations with fragment library
  • Improved calculations within the Pitzer-Gwinn approximation (direct calculation of reduced mass matrix)
  • Monte Carlo calculation for the TD functions of internal rotations
  • Currently Moltran support the following data file formats:
    • Gaussian09 output (automatic recognition)
    • Gaussian03 output (automatic recognition)
    • Gaussian94 output (automatic recognition)
    • Gaussian z-matrix input (/gz<skip lines> command line keyword)
    • Gaussian Cartesian matrix input (/x<skip lines> command line keyword)
    • PC GAMESS v.6 and higher output (automatic recognition)
    • GAMESS US (automatic recognition)
    • Priroda v.8 and higher
    • CFOUR v.1 and higher
    • Various XYZ file formats (/nxyz<skip lines>, /dnxyz<>, /ndxyz<>
    • Any files with NXYZ matrices with search the matrix by label (/nxyzs<skip lines>@<label>)

KinTran is a program plug-in for Moltran for calculations of the reaction thermodynamics and kinetic constants of elementary reactions.

MOLTRAN citation. If you publish the results obtained with Moltran please reference it as follows:

S.K. Ignatov, Moltran v.2.5 — Program for molecular visualization and thermodynamic calculations , University of Nizhny Novgorod, 2004,

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