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Introduction
The QuanteMM module combines enhanced functionalities of the quantum mechanical calculation modules Turbomole, DMol and Mopac with the capabilities of the molecular mechanics program Discover_3 to prepare and perform calculations where a molecule, modeled by quantum mechanics, is embedded into an environment modeled by molecular mechanics.
Introduction
In the study of many complex molecular or crystalline systems of technological and scientific interest, presently available computational resources do not support the routine application of quantum mechanical ab initio methods. These systems are often studied by constructing molecular models that represent only a small portion of the structure yet capture most of the electronic effects which are expected to be important. Such an approach would describe the active site of an enzyme or an acidic site within a zeolite by a molecular model that includes the atoms closest to the studied site. As quantum mechanical computational demands increase at a rate proportional to the third power of the number of atoms in the system, the size of such models is necessarily limited. Furthermore, effects due to the remainder of the structure are neglected.
The hybrid QM/MM scheme of the QuanteMM module takes environmental effects into account by coupling the quantum mechanical description of the molecular model with a molecular mechanical description of the interactions between the molecular model and its actual environment. This concept extends the range of ab initio methods towards systems in which the environment of the molecular model is essential such as in the study of solute-solvent interaction, where the solute molecule is modeled by a quantum mechanical method.
Last updated October 06, 1997 at 10:26PM PDT.
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