• Download

    Critic2 is distributed as ready-to-run packages for Windows, macOS, and Linux that contain the graphical interface (GUI) and the command-line program. Installing them needs no compilers, libraries, or environment variables. The packages correspond to the latest release of critic2. To get the development version, or to run critic2 on a system not covered here, build it from source.

    Windows

    Download the Windows installer

    For 64-bit Windows 10 and 11 (it also works on Windows 7).

    1. Run the downloaded critic2-windows-setup.exe. Windows may show a blue “Windows protected your PC” window, because the installer is not digitally signed. Click More info and then Run anyway.

    2. Follow the installer. If you want to use critic2 from the command prompt, choose the option that adds critic2 to the system PATH.

    3. Start critic2 from the Start Menu (or the desktop icon):

      • critic2 opens the graphical interface. You can also drag a structure file onto the icon to open it.
      • critic2 (console) opens a command window running critic2 interactively.
      • critic2 (software rendering) is the graphical interface for computers whose graphics card or driver does not support it (old computers, virtual machines, remote desktop sessions). Use it if critic2 shows an OpenGL error or does not open.

    To run critic2 on an input file, open a command prompt or a PowerShell window and use:

    critic2 input.cri output.cro

    Portable version. If you cannot (or do not want to) run an installer, download the zip file, unpack it anywhere (a USB drive works too), and double-click critic2.exe in the unpacked folder. The other two launchers, critic2 (console).exe and critic2 (software rendering).exe, are next to it.

    macOS

    On macOS, critic2 is installed with Homebrew, the most common package manager for the Mac. All steps below are commands that you type (or paste) in the Terminal application: press Cmd-Space, type Terminal, and press Return.

    1. Install Homebrew, if you do not have it already: 
      /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

      The installer asks for your password (the one you use to log in to your Mac; nothing appears on the screen while you type it, this is normal) and installs Apple’s command line tools if they are missing. At the end, it prints a “Next steps” section with a few commands; run them, otherwise the brew command will not be found. Check that it works with brew --version.

    2. Install critic2: 
      brew install aoterodelaroza/critic2/critic2
    3. Start the graphical interface, optionally with one or more files: 
      critic2 -g
critic2 -g structure.cif

    On Apple Silicon Macs with macOS 14 or newer and Intel Macs with macOS 15 or newer, Homebrew downloads a ready-made critic2 and the installation takes a minute or two. On older systems, Homebrew compiles critic2 on your Mac, which takes longer.

    To update critic2 and everything else installed with Homebrew, run brew upgrade. To install the current development version instead of the latest release, use brew install --HEAD aoterodelaroza/critic2/critic2. To remove critic2, use brew uninstall critic2.

    Some tips:

    • Apple Silicon processors have performance and efficiency cores. In parallel runs, critic2 usually works best with as many threads as performance cores (four in the M1). To make this permanent, add the OMP_NUM_THREADS variable to your ~/.zprofile: 
      echo 'export OMP_NUM_THREADS=4' >> ~/.zprofile

    • Input files must be plain text. If you use TextEdit to write them, convert the document to plain text first (Format > Make Plain Text); otherwise, TextEdit saves rich text and changes the quotes, and critic2 will not be able to read the file.

    • The graphical interface must be launched from a terminal on the Mac’s own screen (not through an ssh connection).

    If the installation fails, please open an issue and attach the logs (in ~/Library/Logs/Homebrew/critic2/) and the output of brew config.

    Linux

    Download the Linux AppImage

    The AppImage is a single file that contains critic2 and everything it needs. It runs on 64-bit (x86_64) Linux distributions from 2022 or newer (Ubuntu 22.04, Debian 12, Fedora 36, RHEL/Rocky/Alma 10, or later).

    1. Make the downloaded file executable, either in the file manager (Properties > Permissions > Allow executing file as program) or in a terminal: 
      chmod +x critic2-linux-x86_64.AppImage
    2. Double-click it to open the graphical interface.

    The AppImage is also the critic2 command. Run it from a terminal with the same arguments you would give to critic2:

    ./critic2-linux-x86_64.AppImage input.cri output.cro
./critic2-linux-x86_64.AppImage -g structure.cif

    It is convenient to rename it to critic2 and move it to a directory in your PATH (for instance, ~/.local/bin or ~/bin).

    If the AppImage does not start and complains about FUSE, install the FUSE 2 library (sudo apt install libfuse2 in Ubuntu 22.04, libfuse2t64 in Ubuntu 24.04 and later), or run it with the --appimage-extract-and-run option.

    Command line only (computing clusters). The portable tarball contains the command-line program without the graphical interface. It needs neither FUSE nor X11/OpenGL, so it runs on the compute nodes of a cluster:

    tar xzf critic2-linux-x86_64.tar.gz
export PATH=$PWD/critic2-linux-x86_64/usr/bin:$PATH
critic2 input.cri output.cro

    The tarball has the same requirements as the AppImage on the Linux version. On older systems (e.g. RHEL/Rocky 8 or 9), compile critic2 from source.

    Using the graphical interface

    When the graphical interface opens, use File > Open to read a structure or a calculation output, or pass the files on the command line (critic2 -g file1 file2 ...). Critic2 reads many file formats. The Tree window lists the loaded systems and the View window shows the selected one; the Tools menu has the analysis tools, and the Input and Output windows give access to the full critic2 command language (see the quick start guide and the manual).

    On HiDPI (high pixel density) displays, the interface is scaled using the factor reported by the operating system. If it comes out too small or too large, set the CRITIC2_UI_SCALE environment variable (1.0 means no scaling; higher values make the interface bigger). For instance, in Linux and macOS:

    CRITIC2_UI_SCALE=1.5 critic2 -g

    Suggestions and bug reports are welcome in the issue tracker.

    Running in parallel

    Critic2 is parallelized with OpenMP. By default, it uses all the available cores; set the OMP_NUM_THREADS environment variable to choose the number of parallel threads.

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