Marcel J. de Groot, Remco W. A. Havenith, H. Maarten Vinkers, Renate Zwaans, Nico P. E. Vermeulen, Joop H. van Lenthe. Ab initio calculations on iron-porphyrin model systems for intermediates in the oxidative cycle of cytochrome P450s. Journal of Computer-Aided Molecular Design, 12(2):183-193, 1998. [doi]