Quantum chemical studies of spin crossover polymers: Periodic DFT approach

The periodic DFT method has been used to analyze the energetics and the structure of the spin crossover coordination polymer [Fe(pyim)(2)(bpy)](ClO4)(2) center dot 2C(2)H(5)OH (pyim=2-(2-pyridyl)imidazole). It is shown that quantum chemical calculations are able to predict correctly the ground state and internal geometry of the zigzag chain polymer, whereas the description of the interchain space is less satisfactory. The calculations display the role of intermolecular interactions in tuning the energy gap between high-spin and low-spin states. (C) 2008 Elsevier Ltd. All rights reserved.