Loch-E is a research tool for modelling pressure–composition–isotherm (PCI) behaviour of FeTiHₓ hydrides using ab initio energetics and explicitly selectable entropy contributions.
The tool computes equilibrium hydrogen pressures as a function of hydrogen content and temperature, with transparent control over which thermodynamic terms are included in the pressure calculation:
- formation (enthalpy) term
- configurational entropy
- vibrational entropy
- gas-phase entropy
Experimental data is taken from:
Loch-E produces thesis-quality plots and exportable numerical tables via a graphical user interface.
Loch-E is a name, not an acronym.
- α and β phase modelling for FeTiHₓ
- Temperature range: 313–373 K
- Log-scale PCI plots (equilibrium pressure vs composition)
- User-selectable entropy terms for equilibrium pressure calculations
- Explicit entropy decomposition (Svib, Sconf, Sgas, Stot)
- Experimental absorption/desorption overlay
- Exportable results tables:
- formation energies and entropy components
- equilibrium pressures from selected and individual entropy contributions
- Copyable (TSV) and exportable (CSV) tables
- GUI-based workflow (Tkinter)
- Publication-ready plot styling (colour or black & white)
- Python ≥ 3.9
- NumPy
- Matplotlib
- Tkinter (included with standard Python on macOS and most Linux systems)
git clone <repo-url>
cd PCI_Plotter
python -m venv venv
source venv/bin/activate
pip install -r requirements.txtRun the main application:
python LOCH_E.pyFrom the GUI you can:
- Select temperatures (313–373 K)
- Enable α and/or β phases
- Set site counts (
N_alpha_sites,N_beta_sites) - Select which entropy terms contribute to equilibrium pressure:
- vibrational entropy (Svib)
- configurational entropy (Sconf)
- gas-phase entropy (Sgas)
- View a live legend tag indicating the active thermodynamic model
(e.g.α – 323 K [H+vib+conf]) - Toggle plot types:
- pressure vs composition
- entropy components vs composition
- Enable black & white plotting mode
- Set axis limits (optional)
- Enable results tables
- Choose hydrogen composition definition:
xmol— hydrogen mol fractionxH— hydrogen per FeTi
Plots are displayed interactively and can be saved as high-resolution PNG files.
When “Show results tables” is enabled, Loch-E opens a separate results window with multiple tabs.
Columns include:
- phase
- temperature (K)
- hydrogen composition (
xmolorxH) - formation energy (kJ/mol f.u.)
- vibrational entropy (Svib)
- configurational entropy (Sconf)
- gas-phase entropy (Sgas)
- total entropy (Stot)
Columns include:
- phase
- temperature (K)
- active entropy terms (e.g.
H+vib+conf) - hydrogen composition
- equilibrium pressure using selected entropy terms
- equilibrium pressure from:
- formation energy only
- formation + gas entropy
- formation + configurational entropy
- formation + vibrational entropy
- formation + total entropy
Tables can be:
- copied directly to clipboard (TSV)
- exported as CSV files
PCI_Plotter/
├── LOCH_E.py
├── alpha.py
├── beta.py
├── data/
│ ├── expt.py
│ ├── expt_untreated.py
│ └── codesando.py
├── version_1.0/
│ └── v0_Loch_E.py
├── loch_e_logo.png
├── requirements.txt
├── README.md
├── CHANGELOG.md
├── CITATION.cff
├── .gitignore
└── .gitattributes
Current version:
v1.3 (January 2026)
See CHANGELOG.md for details.
Lekshmi Dinachandran and Anna Garden,
Loch-E: Ab initio PCI modelling for FeTiHₓ,
University of Otago, 2026.
Version 1.3.
- Lekshmi Dinachandran
- Anna Garden
University of Otago
January 2026
Loch-E is a research tool intended for scientific analysis.
Users are responsible for validating all results against reference data and experimental benchmarks before reporting or publication.
Loch-E is a name, not an acronym.