DEWPython: A Python Implementation of the Deep Earth Water Model

Abstract

Link to code:https://github.com/chandr3w/DEWPython Authorship StatementChan coded DEWPython and wrote the manuscript. Melwani Daswani aided in writing the manuscript, resolving coding issues, provided scientific motivation, and revised the manuscript. Vance served as the advisor to the project and revised the manuscript.

Electrical Conductivities and Association Constants in Dilute Aqueous NdCl3Solutions from 298 to 523 K along an Isobar of 25 MPa

“…Figure compares the association constants calculated based on the DEW model ,, and empirical correlations by Gammons et al The first association constant K NdCl is between the prediction by Migdisov and Williams-Jones and by Gammons et al, while the second association constant K NdCl 2 is consistent with the results by Migdisov and Williams-Jones at low temperatures, but becomes close to the data calculated from the polynomial correlation proposed by Gammons et al This noticeable discrepancy again demonstrates the difficulty in obtaining the second association constant. To correlate the association constant data, the density model proposed by Mesmer et al was adopted.…”

“…The crystallographic radii taken from Marcus were mainly used to fit the experimental data except those at 298 K (see section ). The first and the second association constants between Nd and Cl ions ( K NdCl and K NdCl 2 ) were initially estimated using the DEWPython module . The DEW parameters provided by Migdisov and Williams-Jones and those by Haas et al were used as initial estimates of K NdCl and K NdCl 2 .…”

“…REE solutions at elevated temperatures have been mainly studied based on other theoretical/empirical methods. Using experimental data at 298 K and 1 bar, Haas et al proposed thermodynamic parameters for predicting thermodynamic properties of rare earth solutions from 1 to 5000 bar, and 273 to 1273 K based on the deep earth water (DEW) model (also known as the extended Helgeson-Kirkham-Flowers model). − Gammons et al derived the association constants from solubility experiments and reported that a higher degree of association occurs at high temperatures, compared to the theoretical results proposed by Haas et al and Wood et al Migdisov and Williams-Jones conducted an ultraviolet spectroscopic study to estimate the association constants. Their results suggest that the first and the second association constants between neodymium and chloride should be lower than that of Haas et al at low temperatures, while they become higher at elevated temperatures.…”