I think this really depends on how dftd4 was built. If I build dftd4 (with meson) without building multicharge mctc-lib etc... then my libdftd4.so comes with all dependencies included and everything works just fine, even when building vasp (verified recently with vasp v6.5.0).

Unfortunately the new suggestion throws an error when dftd4 is built as a standalone library:

$ pkg-config --libs dftd4 multicharge mctc-lib
Package multicharge was not found in the pkg-config search path.
Perhaps you should add the directory containing `multicharge.pc'
to the PKG_CONFIG_PATH environment variable
No package 'multicharge' found
Package mctc-lib was not found in the pkg-config search path.
Perhaps you should add the directory containing `mctc-lib.pc'
to the PKG_CONFIG_PATH environment variable
No package 'mctc-lib' found

Can you please check if the following also fails with your setup?

LLIBS += $(shell pkg-config --libs dftd4) -lmulticharge -lmctc-lib -lmstore

No, that fails unfortunately.

ld: cannot find ld-lmulticharge: cannot find : -lmulticharge: No such file or directory

Thanks for testing. I reverted the changes introduced in this PR and only added the additional linking flags as a hint (#280).