CCSD wavefunction checkpoints for "Natural Orbital Correlation Analysis of Cluster Bonding"

Raw coupled-cluster singles-and-doubles (CCSD) wavefunction checkpoints underlying the electron-correlation analysis in "Natural Orbital Correlation Analysis of Cluster Bonding: From Aromatic Clusters to Metallic Superatoms with Quantum Topology Probes" (C. Arda; preprint 10.26434/chemrxiv-2025-bnp0l-v2; under review at ACS Omega). Each *_checkpoint_ccsd.pkl is a Python pickle (PySCF 2.12.1) of a dictionary with keys: dm1 - CCSD one-particle reduced density matrix (MO basis) t1, t2 - cluster amplitudes e_corr, e_tot - correlation and total energies The reported number of effectively unpaired electrons, N_D = sum_i n_i(2 - n_i) (Takatsuka-Head-Gordon index), is obtained by diagonalizing dm1 to natural-orbital occupation numbers n_i and summing. Reproduction: 1. git clone https://github.com/c-arda/fbond-superatom-aromaticity 2. place these .pkl files under cloud_checkpoints/ 3. run: python extract_fe_from_checkpoints.py That repository also contains the analysis code, optimized geometries, and the post-processed natural-orbital occupation arrays. Contents (CCSD/def2-SVP unless noted): Al4_2minus, Al4_4minus (singlet), Al4_4minus_triplet, B12_planar, B12_icosahedral, B6N6_planar, C6H6_benzene, Cs3Al8, Cs3Al12 (metallic superatoms). Au13_minus: HF checkpoint only - def2-SVP cannot accommodate Au13- (Nocc > Nmo), so the value reported in the paper uses LANL2DZ with the Hay-Wadt LANL2DZ-ECP. Basis sets / ECPs: main-group atoms def2-SVP; cesium def2-ECP; gold LANL2DZ + LANL2DZ-ECP. Not included (available from the author on request): the B12N12 cage CCSD checkpoint, and the def2-TZVP validation amplitude files. v2: corrected three Al4 geometries (Bohr read as Angstrom in v1; N_D 2.54 / 2.53 / 4.34); added the Cs3Al12 CCSD natural-orbital array backing N_D 7.10. See the published article and its Supporting Information.