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Updated: Jun 12, 2025

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Accurate and reliable thermochemistry by data analysis of complex thermochemical networks using Active Thermochemical
Branko Ruscic1, David H Bross1
1Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois, USA. ruscic@anl.gov.
Abstract:
Active Thermochemical Tables (ATcT) were successfully used to resolve the existing inconsistencies related to the thermochemistry of glycine, based on statistically analyzing and solving a thermochemical network that includes >3350 chemical species interconnected by nearly 35 000 thermochemically-relevant determinations from experiment and high-level theory. The current ATcT results for the 298.15 K enthalpies of formation are -394.70 ± 0.55 kJ mol-1 for gas phase glycine, -528.37 ± 0.20 kJ mol-1 for solid α-glycine, -528.05 ± 0.22 kJ mol-1 for β-glycine, -528.64 ± 0.23 kJ mol-1 for γ-glycine, -514.22 ± 0.20 kJ mol-1 for aqueous undissociated glycine, and -470.09 ± 0.20 kJ mol-1 for fully dissociated aqueous glycine at infinite dilution. In addition, a new set of thermophysical properties of gas phase glycine was obtained from a fully corrected nonrigid rotor anharmonic oscillator (NRRAO) partition function, which includes all conformers. Corresponding sets of thermophysical properties of α-, β-, and γ-glycine are also presented.
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