Installation of Environ-0.1 and Environ-0.2

The archive of Environ can be downloaded from the QE-Forge portal. After extraction of the archive (e.g. 'tar -xzf Environ-0.1.tgz'), the Environ/ directory needs to be placed inside the main directory of the Qauntum-ESPRESSO (QE) distribution that requires to be patched. In the following such a directory will be referred to as QE-main-dir.

Installation instructions are summarized in the README file inside the main Environ/ directory and reported in the following:

Preliminary steps:

     -1. Configure QE following the standard procedure (running './configure' from QE-main-dir should be enough in most cases).

      0. Compile QE without the Environ module (running 'make pw' from QE-main-dir).

If there are problems with the preliminary steps, look up for solutions on the PW forum or Quantum-Espresso webpage.

For PW and NEB:

      1. In QE-main-dir/ run the script

        ./install/ Environ Environ/src Modules -patch

      2. In QE-main-dir/PW/src dir run 

        ../../Environ/patches/ -patch

      3. In QE-main-dir/install/ dir run

        ./ -addson Modules Modules

        ./ PW/src

      4. In QE-main-dir re-compile pw.x and neb.x
                     make pw
                     make neb
      5. Run pw.x (or neb.x) with -environ flag, e.g.

                     pw.x -environ < pwinput > pwoutput
      6. In the QE-main-dir/make.sys file generated by ./configure add -D__ENVIRON to the MANUAL_DFLAGS variable.
      7. In QE-main-dir/install/ dir run  
                    ./ TDDFPT/src
      8. In QE-main-dir compile tddfpt

                     make tddfpt
      9. Run the executables with -environ flag.

For CP (only starting from QE-5.3.0): 

     10. In CPV/src dir run
     11. In install dir run
                 ./ CPV/src
     12. In QE main dir re-compile cp
               make cp
     13. Run cp.x with argument cp.x -environ


It is possible to revert the Quantum-ESPRESSO package to a pristine (Environ-free) state by following these steps:
     1. In QE main dir run the script
                      ./install/ Environ Environ/src Modules -revert
     2. In PW/src dir run 
               ../../Environ/patches/ -revert
     3. In CPV/src dir run
                       ../../Environ/patches/ -revert
     4. Be sure to remove objects, modules and executables
                        make clean