Thank you for your response.
I always use the serial version first when developing a new project, but I suppose that is a matter of procedure.
Your question about how to make to two versions is exactly my point.
The old method of compiling yields for me:
/home/rossi/Downloads/workshop/charmm/c42b1/exec/gnu_M/charmm ---> parallel version
/home/rossi/Downloads/workshop/charmm/c42b1/exec/gnu/charmm ---> serial version
and compiling is performed easily with just one switch change.
I would like to add the following to my original post:
----> Documentation ---> installation
Most of the content under installation refers to the old manner of compiling. Perhaps, it might be better to remove that material, and add the new information for cmake.