Interacting Quantum Atoms Approach and Electrostatic Solvation Energy: Assessing Atomic and Group Solvation Contributions

• Published in: Chemphyschem Vol. 19; no. 24; pp. 3425 - 3435
• Main Authors: Jiménez‐Grávalos, Fernando, Díaz, Natalia, Francisco, Evelio, Martín‐Pendás, Ángel, Suárez, Dimas
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 19.12.2018
• Subjects: atomic properties; computational Chemistry; Decomposition; Energy; Mapping; Organic chemistry; Quantum chemistry; Quantum theory; Solvation; Solvents; thermodynamics; quantum chemistry; thermodynamics; computational Chemistry; atomic properties; solvation
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201800733

The interacting quantum atoms (IQA) method decomposes the total energy of a molecular system in terms of one‐ and two‐center (atomic) contributions within the context of the quantum theory of atoms in molecules. Here we incorporate electrostatic continuum solvent effects into the IQA energy decomposition. To this end, the interaction between the solute electrostatic potential and the solvent screening charges as defined within the COSMO solvation model is now included in a new version of the PROMOLDEN code, allowing thus to apply IQA in combination with COSMO‐quantum chemical methods as well as to partition the electrostatic solvation energy into effective atomic and group contributions. To test the robustness of this approach, we carry out COSMO‐HF/aug‐cc‐pVTZ calculations followed by IQA calculations on more than 400 neutral and ionic solutes extracted from the MNSol database. The computational results reveal a detailed atomic mapping of the electrostatic solvation energy that is useful to assess to what extent the solvation energy can be decomposed into atomic and group contributions of various parts of a solute molecule, as generally assumed by empirical methodologies that estimate solvation energy and/or logP values. Solvation energy decomposed: Electrostatic continuum solvent effects are incorporated into the IQA energy decomposition. Applying IQA in combination with COSMO‐QM methods partitions the electrostatic solvation energy into effective atomic/fragment contributions.