Density-functional, density-functional tight-binding, and wave function calculations on biomolecular systems.

Area of Science:

• Computational chemistry
• Biomolecular modeling
• Quantum chemistry

Background:

• Density-functional theory (DFT) methods are widely used for biomolecular studies.
• Incorporating empirical dispersion corrections is crucial for accurate modeling of non-covalent interactions.
• DFT-D and SCC-DFTB-D are recent computational approaches combining DFT with dispersion corrections.

Purpose of the Study:

• To evaluate the performance and usability of DFT-D and SCC-DFTB-D for biomolecular research tasks.
• To compare these methods against high-level ab initio calculations and experimental data.
• To determine suitable applications for each method based on their accuracy and computational cost.

Main Methods:

• Application of DFT-D and SCC-DFTB-D methods to biomolecular systems.
• Calculation of interaction energies for small biomolecular complexes.
• Analysis of structures and infrared spectra.
• Comparison with correlated ab initio methods and experimental results.

Main Results:

• Excellent agreement between DFT-D/SCC-DFTB-D and reference ab initio data for interaction energies of small complexes.
• Good concordance among DFT-D, SCC-DFTB-D, and experimental data for interaction energy, structure, and IR spectra in real-life studies.
• Favorable computational time demands for both methods.

Conclusions:

• DFT-D and SCC-DFTB-D are reliable and efficient computational tools for biomolecular research.
• These methods provide accurate interaction energies, structures, and spectra.
• Specific application areas are proposed for DFT-D and SCC-DFTB-D based on their performance and efficiency.