Rmcprofile

rmcprofile-skill 0.5.5

A Python toolkit around RMCProfile, the Reverse Monte Carlo program for total scattering (rmcprofile.ornl.gov). It reads and writes every input and output format of version 6.7.9 (references/formats.md), checks an input set for the mistakes the manual warns about, runs the binary the user installed, and analyses configurations on its own (references/method.md), cross-checks itself against the installed package (scripts/upstream_adapter.py) and carries a small clean-room RMC engine for teaching (scripts/rmclite.py, references/rmclite.md). RMCProfile is closed-source and distributed under its own "non-profit purposes" terms; this skill never ships or copies it — it finds it through RMCPROFILE_HOME (references/package.md). Read references/pitfalls.md before touching a run directory. Run everything from the product root with the rmcprofile conda env and PYTHONIOENCODING=utf-8; every flag is listed in AGENTS.md.

1. Set up and verify

scripts/install_rmcprofile_windows.ps1        # or scripts/install_rmcprofile.sh; both accept a dry-run
export RMCPROFILE_HOME=/path/to/RMCProfile_package    # the directory holding exe/ and tutorial/
python scripts/verify_rmcprofile.py           # imports, formats, Keen identity, rock-salt shells, package smoke test

The package is downloaded by the user from rmcprofile.ornl.gov/download/ (SourceForge) and unpacked; without RMCPROFILE_HOME every package-bound check and test is skipped, not failed. verify_rmcprofile.py exits 0 only when every check passes; its smoke test copies tutorial/ex_1 to a temp dir and runs it (a few seconds, χ²/dof 0.4201 on both builds).

2. Check an input set before running

python scripts/rmcprofile_tools.py check STEM --dir RUNDIR

Prints one line per finding, LEVEL code: message, exit 1 on any ERROR. Codes: no-dat, dat-parse, no-configuration, rmc6f-parse, atom-order (ATOMS :: and the configuration disagree), minimum-distances-count, maximum-moves-count, data-file-missing, data-file-parse, data-block-no-filename, bragg-file-missing, bragg-inst-missing, bragg-back-missing, bragg-parse, poly-file-missing (the program would wait forever), bulk-rho-missing (PARTICLE_RADIUS :: without BULK_RHO ::, the program stops); warnings end-point-beyond-data, filename-case (Linux/macOS would not find the file), no-weight, hkl-range-unspecified, stale-neighbour-files, history-file (a .his6f from a zero-move pass poisons the next run); info potential-lists-regenerated, summary.

3. Run RMCProfile and read the result

python scripts/rmcprofile_tools.py run STEM --dir RUNDIR --timeout 10      # minutes; --home overrides RMCPROFILE_HOME

The checker runs first and refuses to start on an error. The run's stdout goes to RUNDIR/run.log; the summary line gives the return code, wall time and the number of output files; final: echoes the last row of <stem>.chi2. In Python: res = run_rmcprofile(stem, rundir, find_package()) → res.returncode, res.seconds, res.outputs, res.final_chi2. Read the fit with read_csv_pair("<stem>_PDF1.csv") (r, calc, expt), read_partials_csv("<stem>_PDFpartials.csv"), read_chi2_history("<stem>.chi2"). A missing configuration makes RMCProfile stop with exit code 0 — trust outputs and final_chi2, not the code.

4. Prepare data files

from rmcprofile_tools import write_data_file, read_data_file
write_data_file("sample_gr.dat", r, G, "sample 300 K", style="two-line")   # or style="stog"

DATA_TYPE/FIT_TYPE are G(r), D(r), T(r) in real space and F(Q), S(Q), i(Q) in reciprocal space; the definitions, the r → 0 identity G(0) = −(Σ c_i b_i)² and the weights are in references/method.md. A G(r) whose low-r plateau is not −(Σ c b)² was not normalised the way RMCProfile expects.

5. Build or edit a .dat

from rmcprofile_tools import read_dat
d = read_dat("sample.dat")
d.set("NEUTRON_REAL_SPACE_DATA", "WEIGHT", "0.02")
d.scalars["TIME_LIMIT"] = "30.00 MINUTES"
d.write("sample.dat")

DatFile keeps scalars, the ATOMS :: line and every block in file order and writes them back byte-stable; d.get(block, key), d.data_blocks(), d.filenames(). The block-versus-scalar rule and every keyword seen in the package are in references/formats.md. Keep NUMBER_DENSITY equal to the configuration's header density.

6. Analyse a configuration without the binary

python scripts/rmcprofile_tools.py pdf    FILE.rmc6f --rmax 8 --dr 0.02 --qmax 30 --dq 0.02 --radiation neutron --outdir out
python scripts/rmcprofile_tools.py coord  FILE.rmc6f --pair Na Cl --rmax 3.0
python scripts/rmcprofile_tools.py angles FILE.rmc6f --triplet Na Cl Cl --rmax 3.0 --dangle 2 --outdir out

pdf writes <stem>_PDFpartials.csv (g_ij), <stem>_GofR.csv (Keen's G(r) in barn) and <stem>_FofQ.csv; coord prints the coordination histogram; angles writes the B-A-C angle histogram. Sanity check: the first value of G(r) must be −(Σ c_i b_i)² (−0.2759 barn for SF6). In Python: read_rmc6f, partial_gr, total_gr, fq_from_gr, coordination, bond_angles, average_cell, NEUTRON_B. --rmax must stay below half the shortest supercell edge.

7. Pitfalls

references/pitfalls.md: the .poly wait, exit code 0 on a fatal error, .his6f precedence, stale neighbour files, the CUDA-versus-CPU move rate, /mnt/* slowness under WSL, the two .rmc6f atom-line layouts, CRLF, the r-grid convention, natural-abundance weights, cp1252 consoles.

8. Cross-check against the installed package

python scripts/upstream_adapter.py list                      # the eight shipped exercises and their staging recipes
python scripts/upstream_adapter.py crosscheck ex_1 --timeout 3

crosscheck stages the exercise's pristine inputs in a scratch directory (outputs removed, .poly/.fs/.sf kept, ex_7's TIME_LIMIT cut to 5 min), runs the package, then compares our partials and Keen G(r) for the resulting .rmc6f with the package's own _PDFpartials.csv and _PDF1.csv. "within tolerance: True" means every pair is within tolerance_partials (1e-3; the package computes in single precision, measured 2.8e-4 on the g = 20 peak) and G(r) within tolerance_gofr (1e-4 barn, measured 3e-5) of tests/records/crosscheck_v1.json. --update-records rewrites the measured maxima and provenance — only after a deliberate re-measurement. In Python: crosscheck_partials(rmc6f, partials_csv), crosscheck_gofr(rmc6f, pdf_csv), stage_exercise, run_and_crosscheck.

9. Teach with rmclite

python scripts/rmclite.py synth truth.rmc6f --displace 0.05 --rmax 5 --outdir out     # targets of truth + a displaced copy
python scripts/rmclite.py fit   average.rmc6f --target out/truth_target_PDFpartials.csv --moves 3000 --sigma 0.2 --min-dist "Na-Na:3.0,Na-Cl:2.2,Cl-Cl:3.0" --outdir out

fit writes <stem>_fit.rmc6f, <stem>_fit.chi2 (RMCProfile's header m_accepted m_generated m_tested chi2), <stem>_fit_PDFpartials.csv and <stem>_fit_GofR.csv — read them with the same readers as RMCProfile's output. The acceptance rule is Δ = Δχ²/2 + ΔU/k_BT, accept if Δ ≤ 0 else with probability e^(−Δ). Start from the average structure, never from a random distortion; never fit unbroadened (delta-sharp) targets; expect the pair distribution to be reproduced, not the coordinates (references/rmclite.md §5). In Python: Box.from_rmc6f, Histogram, PartialTarget, TotalGTarget, FqTarget, ClosestApproach, DistanceWindow, BondPotential, RmcLite(...).run(n), synth_targets.

10. Read or rebuild the book

chapters/RMCProfile_NN_*.ipynb — eleven executed notebooks (§1–40, index in chapters/README.md): 1 total scattering and the PDF, 2 the RMC algorithm, 3 starting configurations, 4 fitting neutron data with RMCProfile, 5 X-ray and Bragg, 6 constraints and potentials, 7 corrections (the measured forms of RESOLUTION_CORRECTION and PARTICLE_RADIUS), 8 EXAFS / magnetic / diffuse, 9 analysing configurations, 10 benchmarks and ecosystem. Point a user at the chapter, not at a paraphrase: every number in them was computed in the notebook. To rebuild after editing build/part*.py:

python build/assemble.py --which 07          # regenerate one chapter (unchanged notebooks are kept with their outputs)
RMCPROFILE_HOME=... python build/execute.py --which 07   # execute it on the rmcprofile-mc kernel; PASS/FAIL tally in logs/execute.log
python build/gallery.py                      # docs/figures + README gallery
python -m pytest tests/test_notebooks.py -q  # sources, outputs, totals, leaks

11. Teach the course

course/deck/index.html — eleven lectures (L0 why local structure … L10 contributing), flat and linear, every chapter figure under its notebook caption; course/slides.pdf is the same deck without a browser; course/handout/handout.html the A4 companion; course/notes/LECTURER_NOTES.md every slide's notes with its anticipated question. Point a lecturer at course/README.md (syllabus, keys, rebuilding). After re-executing a chapter:

python course/tools/extract_figures.py      # figures + provenance (--check to test)
python course/tools/build_deck.py           # index.html, handout, notes (--check to test)
python course/tools/make_slides_pdf.py      # slides.pdf (Playwright; committed)
python -m pytest tests/test_course.py -q

12. Watch upstream weekly

python scripts/watch_upstream.py --weekly          # SourceForge listing, site pages/posts, conda tools, GitHub neighbours, tracker status
python scripts/watch_upstream.py --snapshot        # record the state without a report
powershell -File scripts/register_watch_task.ps1   # Windows Task Scheduler, Mondays 08:00 (-DryRun, -Remove)

Reports go to <study>/docs/watch/YYYY-WW.md, the snapshot and audit logs to <study>/forum/upstream-watch/ (gitignored). A feed that does not answer is a row in the report and exit 1; read the report before trusting a silent week. The first run (2026-W36) found a 6.8.0-rc.1 candidate on SourceForge that the site's download page did not list.