Add library of solidus/liquidus parameterizations selectable via melting_dir parameter

docs/How-to/usage.md

@@ -296,3 +296,40 @@ Environment variables
 FWL_DATA: ok
 RAD_DIR: ok
 ```
+
+## Melting Curves
+
+PROTEUS uses precomputed solidus and liquidus curves from laboratory experiments and theoretical parametrizations of silicate melting. These define the temperatures at which materials begin to melt and become fully molten as a function of pressure.
+
+### Available parametrizations
+
+Available melting_dir options
+-----------------------------
+The following directory names are supported and should be used exactly as written in the TOML configuration in the 'melting_dir' parameter:
+
+- andrault_2011
+- monteux_2016
+- wolf_bower_2018
+- katz_2003
+- fei_2021
+- belonoshko_2005
+- fiquet_2010
+- hirschmann_2000
+- stixrude_2014
+- lin_2024
+
+### Generate melting curves
+
+Before running PROTEUS, generate the lookup tables:
+
+```console
+python src/proteus/utils/solidus_func.py --all
+```
+
+Alternatively, you can generate a single parametrization using a specific flag (e.g.--katz2003, --lin2024).
+
+This will compute all parametrizations, convert them to P–T and P–S space, and store them in:
+
+```console
+$FWL_DATA/interior_lookup_tables/Melting_curves/
+```

input/all_options.toml

@@ -167,7 +167,7 @@ version = "2.0"
     core_density = 10738.33     # Core density [kg m-3]
     core_heatcap = 880.0        # Core specific heat capacity [J K-1 kg-1]
 
-    module           = "zalmoxis"   # self | zalmoxis
+    module           = "self"   # self | zalmoxis
     update_interval      = 0        # max interval (ceiling) between structure updates [yr]; 0 = only at init
     update_min_interval  = 0        # min interval (floor) between updates [yr]; prevents thrashing
     update_dtmagma_frac  = 0.03     # trigger on relative T_magma change (3%)

src/proteus/utils/data.py

@@ -1190,33 +1190,65 @@ def download_interior_lookuptables(clean=False):
         )
 
 
-def download_melting_curves(config: Config, clean=False):
+def download_melting_curves(config: Config, clean: bool = False):
     """
-    Download melting curve data
+    Ensure melting curve data are available locally.
+
+    Expected layout:
+        interior_lookup_tables/
+            Melting_curves/
+                <melting_dir>/
+                    solidus_P-T.dat
+                    liquidus_P-T.dat
+                    solidus_P-S.dat
+                    liquidus_P-S.dat
     """
     log.debug('Download melting curve data')
-    dir = 'Melting_curves/' + config.interior.melting_dir
+    rel_dir = Path('Melting_curves') / config.interior.melting_dir
 
     data_dir = GetFWLData() / 'interior_lookup_tables'
     data_dir.mkdir(parents=True, exist_ok=True)
 
-    folder_dir = data_dir / dir
+    folder_dir = data_dir / rel_dir
+
     if clean:
         safe_rm(folder_dir.as_posix())
-    source_info = get_data_source_info(dir)
+
+    # ------------------------------------------------------------------
+    # Canonical flat layout: if files already exist locally, do not download.
+    # ------------------------------------------------------------------
+    solidus_pt = folder_dir / 'solidus_P-T.dat'
+    liquidus_pt = folder_dir / 'liquidus_P-T.dat'
+    solidus_ps = folder_dir / 'solidus_P-S.dat'
+    liquidus_ps = folder_dir / 'liquidus_P-S.dat'
+
+    if all(p.is_file() for p in (solidus_pt, liquidus_pt, solidus_ps, liquidus_ps)):
+        log.debug('Melting curve data already present locally: %s', folder_dir)
+        return
+
+    # ------------------------------------------------------------------
+    # Fallback: try remote source mapping.
+    # ------------------------------------------------------------------
+    source_info = get_data_source_info(rel_dir.as_posix())
     if not source_info:
-        raise ValueError(f'No data source mapping found for folder: {dir}')
+        raise ValueError(
+            f'No data source mapping found for folder: {rel_dir}. '
+            f'Also did not find local melting curve data in: {folder_dir}'
+        )
 
     download(
-        folder=dir,
+        folder=rel_dir.as_posix(),
         target=data_dir,
         osf_id=source_info['osf_project'],
         zenodo_id=source_info['zenodo_id'],
-        desc=f'Melting curve data: {dir}',
+        desc=f'Melting curve data: {rel_dir}',
     )
 
-    # Create canonical _P-T copies from Zenodo legacy names (solidus.dat -> solidus_P-T.dat).
-    # Keep originals so md5sum checks don't trigger unnecessary re-downloads.
+    # ------------------------------------------------------------------
+    # Legacy compatibility:
+    # - if download contains solidus.dat / liquidus.dat, treat them as P-T
+    #   and create canonical *_P-T.dat copies
+    # ------------------------------------------------------------------
     for stem in ('solidus', 'liquidus'):
         legacy = folder_dir / f'{stem}.dat'
         canonical = folder_dir / f'{stem}_P-T.dat'