No, they are very different. Not unexpectedly, because Guix is not a fork of Nix.
They start to look similar at the level of compiled derivations, but even the builder scripts are different: in Guix they are compiled Guile scripts whereas in Nix they are Bash scripts.
They start to look similar at the level of compiled derivations, but even the builder scripts are different: in Guix they are compiled Guile scripts whereas in Nix they are Bash scripts.