Quantum Mechanical Techniques for Very Large Molecules

Quantum Mechanical Techniques for Very Large Molecules 

The quantum mechanical techniques discussed so far are typically appUed to moderate-sized molecules (up to about 100 atoms for ab-initio or DFT and up to 500 for semi-empirical MO techniques). However, what about very large systems, such as enzymes or DNA, for which we need to treat tens of thousand of atoms. There are two possible solutions to this problem, depending on the application. 

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