COBRAMM: A Tunable QM∕MM Approach to Complex Molecular Architectures. Modelling the Excited and Ground State Properties of Sized Molecular Systems

Abstract

This contribution describes a new implementation of a general hybrid approach with a modular structure (called COBRAMM: Computations in Bologna Relating Ab‐initio and Molecular Mechanics Methods) that is able to integrate some specialized softwares and acts as a flexible computational environment, thus increasing the flexibility/efficiency of both QM, and MM, and QM/MM calculations. Specifically, QM/MM ground and excited states geometry optimizations, frequency calculations, conical intersection searches and adiabatic/non‐adiabatic molecular dynamics can be performed on a large molecular system, that can be split up to three different layers corresponding to different levels of accuracy. Here we report, together with a description of the method and its implementation, some test examples on very different chemical problems, which span the wide and diversified area of chemistry (from ground to excited states topics) and show the flexibility, general applicability and accuracy of the presented hybrid approach in the modelling of complex molecular architectures.