Data and code for: Ab initio K-hindrance in neutron-rich pf-shell high-spin isomers

KSHELL shell-model data and analysis scripts for the manuscript "Ab initio K-hindrance in neutron-rich pf-shell high-spin isomers: reduced-hindrance systematics and its momentum-transfer dependence" (D. Leonforte, 2026, doi:10.5281/zenodo.23182112). Model space: pf shell for protons, pf + 0g9/2 + 1d5/2 for neutrons above 40Ca, 2ℏω truncation, interaction gxpf1b_g9d5_2c, effective charges ep/en = 1.5/0.5. Contents: the interaction files (including a variant with the νd5/2 cross-shell matrix elements set to zero); KSHELL eigen and transition logs for 64Fe, 66Fe and 64Cr behind Table 1, including repeat runs and the interaction-variation runs; the J-resolved 66Fe gateway map (level summary, 24 transition blocks, and an analysis script that reproduces the deposited map exactly); the σeff folding grid; an independent-diagonalization cross-check on a second architecture. The folder check/ holds build_receipts.py, which recomputes every Table 1 entry, the admixture and mixing-matrix-element ranges and the numerical scatter directly from the logs (Python 3, standard library only), and a claims specification that compares each quoted manuscript value with the recomputed one using the emitall checker of the BootLoops toolkit. Wave-function files and the one-body transition densities behind the form-factor figure are not included. A README maps each manuscript quantity to its file; MANIFEST.sha256 lists checksums.