Hi!
In a COOP calculation you aim to have a description on the interaction between pairs of orbitals or atoms. In order to do that, you need to indicate each pair you are interested to analyze. In your input, in the first line after the COOP keyword, the initial number 1 indicates that you are interested in one pair of orbitals/atoms. You still need to indicate a pair of orbitals or atoms to be considered, writing them in separated lines. Consider this example, taken from the Tutorials webpage:
NEWK
6 6
1 0
COOP
1 200 7 14 1 12 0
-1 1
-1 2
END
Here, the two lines before the final END keyword indicate which atoms will be considered (atoms, given that the lines start with a negative value, as stated in the manual page 322). COOP will be evaluated considering the first and second atoms of the systems (with indices 1 and 2). From your previous calculations you can recover the indices of the atoms/orbitals you are interested.
Let me know if this information has been useful
