The procedure to retrieve the Background extension is identical to that of DIAMONDS (see diamonds.readthedocs.io for detailed information), so you can either clone the repository or simply download it as a ZIP file. In this second option, by unpacking the Background-master.zip file you will find a folder labeled Background-master and containing a structure similar to that of the folder Diamonds. First you need to rename the folder as Background, and place it in the same working directory of Diamonds (not inside the Diamonds folder!). This extension needs to be compiled separately from Diamonds, but only after you have compiled Diamonds first. Diamonds is used as a library for this extension. The compilation commands are the same as for Diamonds.
IMPORTANT: Before proceeding with the compilation of the Background code make sure you put the Background folder at the same path level of that of Diamonds. This means that the Background folder has not to be placed inside the Diamonds folder, but inside the parent directory where you placed Diamonds.
Please make sure you read the documentation at diamonds.readthedocs.io before installing and using the code. This extension requires that the DIAMONDS code is first installed in your system. The installation of the Background extension is the same as that done for DIAMONDS.
To run the tutorials provided in the package, please follow the guidelines presented in tutorials/README.md