Fig. 6: Electronic and magnetic characterization of the triradical T.
From: Orbital-symmetry effects on magnetic exchange in open-shell nanographenes
a, b, c STM image (V = 300 mV, I = 100 pA), bond-resolved AFM image, and molecular model of T. d dI/dV spectra acquired at different positions marked with filled circles in (a). e Constant current dI/dV maps acquired at \(\pm\)160 mV for spin excitations (I = 300-500 pA, Vrms = 5 mV) and constant-height dI/dV Kondo map (Vrms = 2 mV) of T. f Schematic spin model with the experimental excitation energies as magnetic exchanges, and spin correlators between three phenalenyl units of T, with the values of 0.028, −0.032 and −0.246 calculated for \( < \varPsi \left|{S}_{z}\left(i\right){S}_{z}\left(j\right)\right|\varPsi > \). g Calculated Heisenberg energy levels of the spin model. h Energy difference between first excited state and open-shell ground state (GS) of T calculated in CAS (3,3) plotted as a function of \(U/{|t|}\,\). The black dotted line indicates the experimental gap of 160 meV for T. i Spin correlator map calculated by selecting an atom i and running over all the other atoms j. The chosen atom i are marked by black arrows. Red/blue denote spin up/down density distribution.
