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Validate

If you want your data to appear on moltsa.com or moltensalts.net, use this page to upload it. Templates are provided on the left, and the column headers are explained below:

Species 1: Provide the chemical formula of species 1 (e.g., NaCl, KCl, UCl₃).

Species 2: Provide the chemical formula of species 2 (e.g., NaCl, KCl, UCl₃).

Mole frac species 1: Enter the mole fraction of species 1 (e.g., 0.00–1.00). The total of all species must sum to 1.00.

Mole frac species 2: Enter the mole fraction of species 2.

Temp (K): Enter the temperature in Kelvin.

deltaH: Enter the enthalpy of mixing in Jmol^–1.

Author: Provide the author(s) of the dataset, ensuring correct spelling and the format Last Name (year). For two authors, use both names separated by “and,” for three or more, use “et al.” (e.g., Smith et al. (2017)).

Type: Provide additional detail about the data (e.g., “liquidus” or “solidus”), or leave it blank.

Link: Provide a DOI link if possible so the data can be verified. Otherwise, include a link to where the dataset is hosted (e.g., ResearchGate).

The templates are designed to accommodate multiple datasets from different authors and chemical systems, allowing you to upload them all at once. Files must be in .csv format with unaltered column headers. After filling in your data, use the file upload system on the left to submit your dataset.

What happens next?

Your data will be verified, including checks for duplicates and correct formatting, and we will reference the original papers where possible. Once verified, your dataset will be added to the moltsa.com/moltensalts.net database.

Download template

Process DSC Data Using the IUPAC Zero-Rate Method with Error Analysis

This page processes raw differential scanning calorimetry (DSC) data. It extracts peak temperatures measured at multiple heating and cooling rates, applies a calibration based on known melting point standards, and computes an error bar for each measured transition.

Templates
Download templates for the data and calibration files using the panel on the left.

Input File Schema

Data file:

mol_frac_X: Mole fraction of interest. This field is flexible and depends on how you wish to visualise the data. It is recommended to use the species that comes later alphabetically, in line with typical phase diagram conventions.

rate: Ramping rate for each set of measurements. Typical values include 16, 8, 4, and 1.6, or 20, 10, 5, and 2 (default units: °C min^–1).

P1, P2, P3...: Peak temperatures (in °C). Add or remove peak columns as needed. If the same peak is detected at multiple rates, list all values in the same column.

ramp_direction: Temperature ramp direction. Accepts heating or cooling.

keep: Optional logical column (TRUE/FALSE). Measurements with keep = FALSE are excluded. Useful for omitting data requiring separate calibrations (e.g. measurements from a different instrument).

Calibration file:

species: Chemical formula of the calibrant (e.g. NaCl, KCl).

R16, R8, R4, R1.6...: Measured transition temperatures for each ramp rate (°C min^–1).

temp_c_temperature: Literature melting point (in °C).

error_in_literature: Reported uncertainty in the melting point.

literature_reference: Citation or source of the literature value.

Testing with Default Datasets

If no data file is uploaded, a default dataset will be loaded for demonstration. If no calibration file is uploaded, the latest calibration file for the Netzsch Pegasus instrument will be applied.

Plots Explained

Measured transitions plot: Shows corrected transition temperatures with error bars representing the total standard error.

Calibration plot: Shows the calibration model used to correct the raw data.

Temperature calibration & error analysis: A downloadable table of all processed data.

Temperature Calibration Explained

• For each calibrant i, the deviation is defined as: \( \Delta T_i = T_i^{measured} - T_i^{literature} \), where \( T_i^{measured} \) is the extrapolated zero-rate onset temperature, and \( T_i^{literature} \) is the known melting point.
• These values \( \Delta T_i \) are linearly interpolated to define the calibration function, which estimates the temperature correction \( T_{correction} \) as a function of \( T_{measured} \).

Error Analysis Explained
Error sources include:

Linear extrapolation to zero rate for sample transitions (standard error of the Y-intercept).

Linear extrapolation to zero rate for calibrant transitions (standard error of the Y-intercept).

Uncertainty in calibrants’ literature melting points (reported standard error).

These standard errors are combined as orthogonal vectors to compute the total standard error.

The CALPHAD_weighting variable is proportional to the inverse of the total standard error and can be used to apply selective weighting in CALPHAD optimisations.

Use this page to download ready-made experiment files (.exp) for CALPHAD optimisations.

Use the search bar on the left to filter by specific elements.
Enable Strict search to exclude files elements not selected.

Use this page to calculate parametric quantities for salts.

Guidelines:

\( \delta_{12} \)

• \( \delta_{12} \), which is readily calculable based on Shannon radii differences, provides an empirical method to predict \( \Delta_{mix}H \) in pseudo-binary salt systems.
• The theory was first used by H. T. Davis, “Theory of Heats of Mixing of Certain Charge‐Unsymmetrical Fused Salts”, The Journal of Chemical Physics, vol. 41, no. 9, pp. 2761–2766, Nov. 1964, doi: 10.1063/1.1726349.
• It is defined as \( \delta_{12}= \frac{\left( r_1^++r_1^- \right) - \left( r_2^++r_2^- \right)}{\left( r_1^++r_1^- \right) \times \left( r_2^++r_2^- \right)} \) and has units of \( Å^{-1} \).
• Shannon radii utilised here originate from R. D. Shannon, “Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides,” Acta Cryst A, vol. 32, no. 5, pp. 751–767, Sep. 1976, doi: 10.1107/S0567739476001551, and were retrieved from the Database of Ionic Radii maintained by the Atomistic Simulation Group, Materials Department, Imperial College (http://abulafia.mt.ic.ac.uk/shannon/ (accessed 2025-02-15).

Calculate parameters and update plot

Use this page to determine Maier-Kelley polynomial coefficients for heat capacity data.

Guidelines:

• Paste your heat capacity data into the table (units are Kelvin and \( JK^{-1}mol^{-1}\))
• Choose up to 2 breaks in the data — the algorithm will fit a stepwise function, using the breaks to define the steps.
• Click the button to update the plot and generate the parameter table.
• Vary the breaks using the slider inputs to obtain a good fit. As an example, using the default dataset, see that break 1 = 350, and break 2 = 1000 produce a great fit of the data.