LAMMPS Windows Installer Packages with support for MS-MPI - Testers needed

Until now, the installer packages with pre-compiled LAMMPS binaries for Windows would use a very old MPICH2 package (version 1.4.1) as MPI runtime. This package is somewhat difficult to set up correctly and with recent Windows versions (10 and 11) it is also needed to enable support for very old .NET versions (which is off by default) in order to run the .msi installer process.

Over the last couple of days, I have found a way to use the much more recent MS-MPI package from Microsoft (version 10.1). This package works without a problem when compiling with the Visual Studio compilers natively on Windows, but the installer packages are built on Linux with a cross-compiler using the MinGW-w64 compilers and those use a different file format for libraries that is not compatible with what is used by MSVC. However, there are tools to reconstruct the files necessary for cross-compilation and after some tweaking and massaging, this seems to be working now.

However, since I have only limited access to Windows machines, I need the help of the LAMMPS user community to confirm that the changes are correct and the executables working properly. Thus I have built a set of new installers that use MSMPI in the name instead of MPI and set them up for download at:

Any previous LAMMPS packages must be uninstalled before installing these. Also, if you had previously installed the MPICH2-1.4.1 package, you must uninstall it, too.

The MPI package you need to use instead is the “msmpisetup.exe” package from Microsoft. You can download it here:

Please provide any feedback by replying to this post.

Update 2022-11-05: The installer packages will now check whether the MS-MPI runtime is installed and stop installation with a dialog box showing the download URL, if not.

1 Like

Hi, so we have to install it with MPI package and run an example script only and report if it runs or not, right?

Dear Axel
I have a DELL Precision 3571 12th with Gen Intel(R) Core™ i9-12900H 2.50 GHz 14 cores OS windows (updated)
I have first uninstall the current LAMMPS version, then the mpich version.
I have then installed MSMPI and then LAMMPS-MSMPI following your links.
I have launched a job in CMD windows with the command :
mpiexec -np 9 lmp -in
All works perfectly. The file is exactly the same as running on my linux server. The log.lammps is filled. The cmd windows is refreshed lately as using mpich, may be after a longer time. But it is not a problem since I can check the logfile which contains more or less the same information and is lively refreshed.
The job is using pair_style eam/alloy.
I will test it in a next future with reaxFF potential and probably meam too. I will also install add the available plugins.
I hope it is useful for you. If you have more needs, I will try to help.

Dear Axel
Iam stopping running jobs and some LAMMPS command is still running as schown with the task manager. See the screenshot below

Else, as in my previous mail, all jobs run fine with this Windows install. I am running under Windows 10. Not yet Windows 11 which is not yet recommended by my institution.

This is the installer program. You probably didn’t click on the “Close” button on the installation log dialog box.