Archaeal Proteins 2 Binding affinities 2 Binding energy 2 Breathing modes 2 Chemical properties 2 Compression-expansion 2 Electronic properties 2 Heme 2 Heme distortion 2 Heme group 2 Heme proteins 2 Hemeproteins 2 Hemoglobin 2 In-plane distortions 2 Ligand affinity 2 Macrocycles 2 Methanosarcina 2 Methanosarcina acetivorans 2 Out-of-plane distortions 2 Oxygen 2 Oxygen affinity 2 Porphyrin rings 2 Porphyrins 2 Quantum Theory 2 Systematic study 2 archaeal protein 2 chemistry 2 heme 2 hemoprotein 2 metabolism 2