Ab initio analysis of the x-ray absorption spectrum of the myoglobin-carbon monoxide complex: Structure and vibrations

TL;DR

This study combines density-functional theory and multiple-scattering simulations to accurately analyze the x-ray absorption spectrum of the myoglobin-CO complex, providing reliable structural insights without fitting parameters.

Contribution

It introduces a synergic approach that integrates DFT and spectral simulation for precise structural determination from high-resolution spectral data.

Findings

Excellent match between experimental and simulated spectra

Reliable determination of CO ligand geometry

Methodology applicable to similar high-resolution spectral analyses

Abstract

We present a comparison between Fe K-edge x-ray absorption spectra of carbonmonoxy-myoglobin and its simulation based on density-functional theory determination of the structure and vibrations and spectral simulation with multiple-scattering theory. An excellent comparison is obtained for the main part of the molecular structure without any structural fitting parameters. The geometry of the CO ligand is reliably determined using a synergic approach to data analysis. The methodology underlying this approach is expected to be especially useful in similar situations in which high-resolution data for structure and vibrations are available.