(a) Experimental and simulated X-band EPR spectrum of the green intermediate. The spectrum was simulated with the following Hamiltonian parameters: gx = 2.0127, gy = 2.0521, gz = 2.1344, Ax =Ay = 47 MHz, and Az = 326 MHz (116 G). (b) X-band EPR spectrum of purple mixed-valence CuA for comparison. Experimental conditions were as follows: frequency 9.400 GHz, temperature 120K, microwave power 2mW, modulation amplitude 4 G, instrument gain 25 db, sweep time 42 s.