Validation of the inverted adsorption structure for free-base tetraphenyl porphyrin on Cu(111) - Ryan, PTP; Lalaguna, PL; Haag, F; Braim, MM; Ding, P; Payne, DJ; Barth, J; Lee, T-L; Woodruff, DP; Allegretti, F; Duncan, DA (CHEMICAL COMMUNICATIONS, 2020)