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Molecular crystals: the crystal field effect on molecular electronic structure
1Department of Chemistry, Moscow State University, 119992 Moscow, Russia. yatsenko@biocryst.phys.msu.su
Journal of Molecular Modeling
|July 3, 2003
Summary
Crystal packing significantly impacts organic molecule electronic structures. This study models these effects, revealing that long-range electrostatic interactions, not just hydrogen bonds, are key, and accurately predicts color differences in polymorphs.
Area of Science:
- Solid-state chemistry
- Computational chemistry
- Molecular modeling
Background:
- Crystal packing influences molecular electronic structure.
- Semiempirical methods often have charge distribution errors.
- Understanding crystal field effects is crucial for predicting molecular properties.
Purpose of the Study:
- To model the effect of crystal packing on organic molecule electronic structure.
- To develop a correction procedure for semiempirical method errors.
- To investigate the origin of crystallochromy.
Main Methods:
- Incorporation of external electrostatic potential into semiempirical Hamiltonian.
- Empirical correction procedure for charge distribution errors.
- INDO/S calculations using crystal electrostatic potential.
Main Results:
- Crystal field effects vary widely with packing motifs.
- Long-range electrostatic interactions are more dominant than hydrogen bonds.
- The model accurately predicts color differences in polymorphs.
Conclusions:
- Crystal packing significantly alters molecular electronic structure.
- The developed model provides insights into crystallochromy.
- This approach aids in understanding solid-state properties of organic materials.