Towards Automated Benchmarking of Atomistic Forcefields: Neat Liquid Densities and Static Dielectric Constants from the ThermoML Data Archive

Atomistic molecular simulations are a powerful way to make quantitative predictions, but the accuracy of these predictions depends entirely on the quality of the forcefield employed. While experimental measurements of fundamental physical properties offer a straightforward approach for evaluating forcefield quality, the bulk of this information has been tied up in formats that are not machine-readable. Compiling benchmark datasets of physical properties from non-machine-readable sources require substantial human effort and is prone to accumulation of human errors, hindering the development of reproducible benchmarks of forcefield accuracy. Here, we examine the feasibility of benchmarking atomistic forcefields against the NIST ThermoML data archive of physicochemical measurements, which aggregates thousands of experimental measurements in a portable, machine-readable, self-annotating format. As a proof of concept, we present a detailed benchmark of the generalized Amber small molecule forcefield (GAFF) using the AM1-BCC charge model against measurements (specifically bulk liquid densities and static dielectric constants at ambient pressure) automatically extracted from the archive, and discuss the extent of available data. The results of this benchmark highlight a general problem with fixed-charge forcefields in the representation low dielectric environments such as those seen in binding cavities or biological membranes

Thermodynamic Properties of N-Methyl-Substituted Ethane-1,2-diamines: Experimental and Computational Study

© 2016 American Chemical Society.Vapor pressures for four N-methyl-substituted ethane-1,2-diamines were measured using the transpiration method. Enthalpies of vaporization were derived from the temperature dependence of the vapor pressures. Consistency of the experimental data was assessed and confirmed with group-additivity (GA) and quantum-chemical (QC) methods. Further confirmation of the results is provided through combined assessment with properties reported in the literature for the parent compound ethane-1,2-diamine and a group of alkyl-substituted alkane-1,2-diamines. The effective application of modern QC methods in critical evaluation of enthalpies of vaporization and enthalpies of formation is demonstrated

Improvement of Quality in Publication of Experimental Thermophysical Property Data: Challenges, Assessment Tools, Global Implementation, and Online Support

Article on the improvement of quality in the publication of experimental thermophysical property data

Thermodynamic Properties of N-Methyl-Substituted Ethane-1,2-diamines: Experimental and Computational Study

© 2016 American Chemical Society.Vapor pressures for four N-methyl-substituted ethane-1,2-diamines were measured using the transpiration method. Enthalpies of vaporization were derived from the temperature dependence of the vapor pressures. Consistency of the experimental data was assessed and confirmed with group-additivity (GA) and quantum-chemical (QC) methods. Further confirmation of the results is provided through combined assessment with properties reported in the literature for the parent compound ethane-1,2-diamine and a group of alkyl-substituted alkane-1,2-diamines. The effective application of modern QC methods in critical evaluation of enthalpies of vaporization and enthalpies of formation is demonstrated

Thermodynamic Properties of N-Methyl-Substituted Ethane-1,2-diamines: Experimental and Computational Study

© 2016 American Chemical Society.Vapor pressures for four N-methyl-substituted ethane-1,2-diamines were measured using the transpiration method. Enthalpies of vaporization were derived from the temperature dependence of the vapor pressures. Consistency of the experimental data was assessed and confirmed with group-additivity (GA) and quantum-chemical (QC) methods. Further confirmation of the results is provided through combined assessment with properties reported in the literature for the parent compound ethane-1,2-diamine and a group of alkyl-substituted alkane-1,2-diamines. The effective application of modern QC methods in critical evaluation of enthalpies of vaporization and enthalpies of formation is demonstrated

Thermodynamic Properties of N-Methyl-Substituted Ethane-1,2-diamines: Experimental and Computational Study

© 2016 American Chemical Society.Vapor pressures for four N-methyl-substituted ethane-1,2-diamines were measured using the transpiration method. Enthalpies of vaporization were derived from the temperature dependence of the vapor pressures. Consistency of the experimental data was assessed and confirmed with group-additivity (GA) and quantum-chemical (QC) methods. Further confirmation of the results is provided through combined assessment with properties reported in the literature for the parent compound ethane-1,2-diamine and a group of alkyl-substituted alkane-1,2-diamines. The effective application of modern QC methods in critical evaluation of enthalpies of vaporization and enthalpies of formation is demonstrated