I’m running Ubuntu 22.04 and trying to run the pre-built Linux executable but getting this error:
./bin/lammps-gui: error while loading shared libraries: libQt5Charts.so.5: cannot open shared object file: No such file or directory
It seems I can’t get QT5 via apt anymore. I’ve installed QT6, together with the additional/optional QT5 backwards compatibility and QTCharts modules from the QT user portal… but the error remains. Any ideas?
I’m not technically a LAMMPS beginner… but its been a few years so I’d really like to start using the GUI as a beginner.
How exactly do you launch LAMMPS-GUI?
I suspect you are not following the instructions and are trying to run the binary directly instead of the wrapper script. The Linux binary package includes the required libraries and the wrapper script sets up using them.
The “safer” alternative is to install flatpak support into your system and then install the flatpak bundle instead.
P.S.: please also let us know which package exactly you downloaded from where.
I tried to get the QT library from Qt Account Login using the online installer, selecting a custom install of 6.10 and selecting the QTCharts and QT5 backwards compatibility check boxes.
@Soph123 would you be willing to make a few tests and experiments to help me checking out a few things about the LAMMPS-GUI packages to make certain that the Linux package for the next LAMMPS release has no problem with LAMMPS-GUI?
Today I started from a completely fresh clean Ubuntu 22.04 build - with none of the “self-help” Qt downloads I tried yesterday - and when I tried the tar.gz version of the pre-built executable, I got the same error as I got yesterday.
Also the flatpak version for the 25 Sept didn’t work either. I got as far as the run instruction (flatpak run org.lammps.lammps-gui) and got this error:
Cannot mix incompatible Qt library (5.15.17) with this library (5.15.15)
That is to be expected. I checked the archive and the library is missing. As mentioned before, this is likely an issue due to the unbundling of LAMMPS-GUI from the LAMMPS sources. It should be resolved with the next LAMMPS feature release.
Download the “plugin” version of LAMMPS-GUI from here: Release Version 1.8.4 · akohlmey/lammps-gui · GitHub . This is missing the LAMMPS shared library, but you can tell it to pick up the one from the 10 September 2025 release with something like this: ./lammps-gui -p /path/to/the/other/folder/lib/liblammps.so.0
I will also create new test packages now and upload them to a temporary location so you can confirm that the packaging has been corrected since the 10 Sep 2025 release. I will post here when those are available. Since we now create “immutable releases”, I cannot change the released package after the fact.
I am also including new standalone LAMMPS-GUI versions 1.8.5 that were released today and include a replaceable LAMMPS shared library. Unlike version 1.8.4, these can be launched without having to point to an external LAMMPS library, but they can use the 10 Sep 2025 release version and this can be selected through the preferences dialog. The “maintenance” and “develop” versions are linked to the LAMMPS library directly and thus it cannot be changed.
All of those should be able to launch LAMMPS-GUI directly.
Try the package from the stable release update here: [Release Update 2 for Stable release 22 July 2025 ·
Failed with error:
/lammps-gui
qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in “” even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: xcb.
Aborted (core dumped)
Download the “plugin” version of LAMMPS-GUI from here: Release Version 1.8.4 · akohlmey/lammps-gui · GitHub . This is missing the LAMMPS shared library, but you can tell it to pick up the one from the 10 September 2025 release with something like this: ./lammps-gui -p /path/to/the/other/folder/lib/liblammps.so.0
FAILED with error:
/lammps-gui -p ~/Documents/LAMMPS/LAMMPS-GUI/lib/lib-lammps.so.0
qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in “” even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
FAILED with error
./lammps-gui
./bin/lammps-gui: error while loading shared libraries: libjpeg.so.62: cannot open shared object file: No such file or directory
Installed with ‘sudo apt-get install -y libjpeg62’
./lammps-gui SUCCESS
I am also including new standalone LAMMPS-GUI versions 1.8.5 that were released today and include a replaceable LAMMPS shared library. Unlike version 1.8.4, these can be launched without having to point to an external LAMMPS library, but they can use the 10 Sep 2025 release version and this can be selected through the preferences dialog. The “maintenance” and “develop” versions are linked to the LAMMPS library directly and thus it cannot be changed.
All of those should be able to launch LAMMPS-GUI directly.
I tried all 3 of the Linux versions in this download site on a different Ubuntu 22.04 machine. ALL 3 failed with the same error:
/lammps-gui
qt.qpa.plugin: Could not load the Qt platform plugin “xcb” in “” even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Apparently, you have a very minimal graphics and X11 library support on your Linux box.
This is not the case for most people after they have installed some commonly used graphical applications.