Abstract
The effective use of partial atomic charge models is essential for such purposes in molecular computations as a simplified representation of global charge distribution in a molecule and predicting its conformational behavior. In this work, ten of the most popular models of partial atomic charge are taken into consideration, and these models operate on the molecular wave functions/electron densities of five diheteroaryl ketones and their thiocarbonyl analogs. The ten models are tested in order to assess their usefulness in achieving the aforementioned purposes for the compounds in title. Therefore, the following criteria are used in the test: (1) how accurately these models reproduce the molecular dipole moments of the conformers of the investigated compounds; (2) whether these models are able to correctly determine the preferred conformer as well as the ordering of higher-energy conformers for each compound. The results of the test indicate that the Merz-Kollman-Singh (MKS) and Hu-Lu-Yang (HLY) models approximate the magnitude of the molecular dipole moments with the greatest accuracy. The natural partial atomic charges perform best in determining the conformational behavior of the investigated compounds. These findings may constitute important support for the effective computations of electrostatic effects occurring within and between the molecules of the compounds in question as well as similar compounds.
Highlights
Partial atomic charges are useful descriptors for interpreting the results of quantum chemical calculations in a chemically intuitive fashion
For the molecular wave functions calculated by HF/def2-QZVPP, the charges from electrostatic potentials (CHELP) model leads to the lowest root mean square error (RMSE) value
The positive values of the mean signed error (MSE) yielded by the MKS, CHELP, charges from electrostatic potentials using a grid (CHELPG) and HLY
Summary
Partial atomic charges are useful descriptors for interpreting the results of quantum chemical calculations in a chemically intuitive fashion. Computation 2016, 4, 3 ranked among the models of the first group In this analysis, the distribution of the molecular electron density is represented by multipoles located on the individual atoms of a molecule. The second group of partial atomic charge models comprises models that partition the molecular electron density into atomic domains in the physical space. The MKS, CHELP and CHELPG schemes differ in the selection of points surrounding a molecule Such points are used for the calculation of the molecular electrostatic potential in the fitting procedure. In the first stage of the present work, various models of partial atomic charge are tested in terms of their ability to reproduce the molecular dipole moments of 1a–5a and 1b–5b.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
