Hydrogen bonds electronic structure calculations

Figure 3. Structural representation of the computational models A-F. Models B, D, and E are combined QM/MM models where the regions enclosed in the dotted polygons represent the QM region. The regions outside the polygons are treated by a molecular mechanics force field. For the electronic structure calculation of the QM region, the covalent bonds that traverse the QM/MM boundary (the dotted polygon), have been capped with hydrogen atoms. In model A the atoms labelled 1 through 4 are the atoms that have been fixed in the calculations of models A through E.

Computational modeling of hydrogen bonding scenarios represents a complex problem. Electronic structure calculations based on quantum mechanical methods provide undoubtedly the most fundamental and reliable framework for reliable... 

Electronic structure calculations at the SCF level were applied to CO2-HF and CO2-HCI with the following results. The CO2-HF and CO2-HCI blue-shifts were reproduced quantitatively 9.9 and 3.9cm , respectively (experimental) versus 9.7 and 3.9cm , respectively (theoretical). The linear hydrogen-bonded equilibrium structures were also confirmed, with little... 

ELECTRONIC STRUCTURE CALCULATIONS ON HYDROGEN-BONDED MOLECULAR SYSTEMS... 

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