Modeling MOFs with Open d-Shells Using Methods Based upon New Semiempirism Concept

Abstract

Use of standard computational modeling techniques on metal-organic frameworks (MOFs) that contain open-d-shell ions is known to be problematic, due to both practical (heavy computational cost) and fundamental (correlated, many-configurational character of open-d-shell states) limitations. To try and overcome these problems, we have embraced a new concept of semi-empiricism which bases the material’s wavefunction representation on the observable components—generalized chromophores—present in the system. Adequate choice of constituent chromophores and description of the interactions between them lead us to develop, in the form of JAKONTOS and \(\Sigma {\text{H}}\Theta \Omega \) programs, of efficient methods for computational modeling capable of reproducing the fine dependence of the transition metal ions’ d-shell spin-states on the spatial structure of the MOF to which they belong. Presented are both a sketch of the underlying theory facilitating this computation and its more formal description. The developed methods allow for a computer-aided screening of MOFs for sensor functionality, as confirmed by the provided computational results.