CCL:G: Relaxed scan using GDIIS with Gaussian

 Sent to CCL by: "Gianluca  Santarossa"
 Dear Jose,
 thanks for your help.
 > You only have to include in calculation route the Modredundant keyword
 instead of Z-matrix. In
 the case of dihedral dih9=N1-N2-N3-N4 your input should be:
 > #P PM3  opt=(tight,gdiis,modredundant) gfinput gfprint IOP(6/7=3) pop=full
 > Then Z-matrix and geometrical parameters.
 > (Blank line)
 > * N2 N3 * R
 > N1 N2 N3 N4 0.000 S 35 10.0
 Nice trick. It perfectly worked.
 > You have more information in G03 Manual, Opt keyword, Relaxed Potential
 You're right, I should have read the manual more carefully, although it is my
 opinion that the lines
 you're referring to should be added to the examples at the end of the page.
 It was confusing for me that the scan just worked with the Z-matrix keyword and
 without the GDIIS,
 while it did not when the GDIIS was turned on.
 Anyway, sorry for the RTFM question, and thanks again.