SCF GIAO Magnetic shielding Degeneracy 0.0 1.0 Shift (ppm) 250 200 150 100 50 0 21-C 2-C 18-C 31-C 26-C 30-C 6-C 9-C 49-C 48-C 34-C 19-C 33-C 24-C 42-C 1-C 14-C 3-C 10-C 35-C Ref