Implements the GGA with spinors
Description
Implements the GGA with spinors. This is done following Peralta, Scuseria, and Frisch, PRB 75, 125119 (2007).
News snippet
Implements the GGA with spinors.
Checklist
-
I have checked that my code follows the Octopus coding standards -
I have added tests for all the new features added in this request.