A while ago I wrote a small tool that translates a subsets of inputs/outputs between Turbomole and Orca, so that the former can be used on any QM/MM engine that supports the latter. I recently added support for the xtb semiempirical package also. It is really a small and simple script, but I post it here in the hope that somebody will find it useful.
I originally wrote the script for the pDynamo QM/MM program, and have only tested it there. Still, there is nothing pDynamo-specific about the script, it simply translates between two QM formats, so I expect it to just work in Gromacs. Of course, do check that things are fine if you use it.
Brief description of tools/files
-A Python script that translates between the Orca QM program and Turbomole or xtb inputs/outputs (only the subsets required for a typical QM/MM calculation).
-A tiny example shell scripts that is called instead of the Orca binary. The script call the Python translation program (for the input), then the target QM program, and then the translation program again
(for the output).
How the work has been tested/reviewed:
Only by my own use so far, but it is a very small/restricted utility