# =====================================================================
#  NEB-TS: Reactant -> Product-1 (aziridine, cpd 16)
#  Level: B3LYP-D3BJ / def2-TZVP  (RIJCOSX + def2/J)
#
#  Atom count/order note: this reaction releases N2 gas. To satisfy
#  ORCA's requirement that both NEB endpoints have identical atom
#  count/order, the leaving N2 (the reactant's terminal azide N-N,
#  same two atoms) has been placed ~18 Angstrom away from the product
#  core in Product-1_NEB.xyz, at the same atom-list positions (31,32) as in
#  the reactant. All 30 "core" atoms are in matched 1:1 order between
#  the two files (verified programmatically from connectivity).
# =====================================================================

! NEB-TS B3LYP D3BJ def2-TZVP def2/J RIJCOSX TightSCF Freq

%pal nprocs 8 end
%maxcore 3000

# ---- Electric field (OEEF) block ----------------------------------
# Uncomment and set direction (x,y,z in atomic units, 1 a.u. ~ 51.4 V/Angstrom)
# to study the field effect on the barrier / selectivity.
# Example: 0.01 a.u. along the molecular z-axis:
#%scf
# efield 0.0, 0.0, 0.01
#end

%neb
  NEB_End_XYZFile "Product-1_NEB.xyz"
  NImages 10
end

*xyzfile 0 1 Reactant.xyz