ORCA Benchmarks

reproducible ORCA benchmark case studies. Each benchmark folder is meant to be readable on its own: geometry, ORCA output files, plots, and a short README with the relevant results.

Hardware

Unless noted otherwise, benchmarks were run on a single dual-socket workstation:

• CPU: 2x Intel Xeon E5-2696 v4
• Physical cores: 44
• RAM: 121 GiB
• ORCA: 6.1.1

Benchmarks

ID	Benchmark	System	Method	Result
001	Porphin core scaling	Porphin, 38 atoms	B3LYP/def2-SVP	TDDFT/TDA and geometry-optimization scaling on the same machine.
002	FeCN6 N K-edge basis comparison	[Fe(CN)6]4-, 13 atoms	TDDFT/TDA, def2-TZVP vs aug-cc-pVTZ on N	Augmenting only the N basis improves PBE0 and CAM-B3LYP; BP86 stays poor.
003	ZnTPP CPCM TDA comparison	ZnTPP, 77 atoms	TDDFT, def2-TZVP, CPCM(toluene)	TDA-on vs full TD-DFT for five representative functionals against the toluene UV-vis spectrum.
004	NiTPP, PdTPP, PtTPP B-band trend	NiTPP, PdTPP, PtTPP, 77 atoms each	Full TD-DFT, def2-TZVP, CPCM(toluene)	The B band blue-shifts monotonically from Ni to Pd to Pt across the five-functional sweep.
005	B-band TDA vs full TD-DFT shift across metals	MgTPP, ZnTPP, CdTPP, NiTPP, PdTPP, PtTPP, 77 atoms each	TDDFT/TDA vs full TD-DFT, def2-TZVP, CPCM(toluene)	TDA blue-shifts the B band for every metal and functional, with smaller shifts for NiTPP, PdTPP, and PtTPP than for MgTPP, ZnTPP, and CdTPP.
006	Porphyrinoid core ladder	Porphin, chlorin, bacteriochlorin	Full TD-DFT, def2-TZVP, CPCM(CH2Cl2)	Across five functionals, the free-base core ladder red-shifts monotonically from porphin to bacteriochlorin.
007	Mg core ladder shifts	Mg-porphin, Mg-chlorin, Mg-bacteriochlorin	Full TD-DFT, def2-TZVP, gas phase and CPCM(CH2Cl2)	Mg insertion blue-shifts porphin and chlorin, but red-shifts bacteriochlorin.
008	Mg-bacteriochlorin axial ligation	Mg-bacteriochlorin with H2O, MeOH, imidazole	Full TD-DFT, def2-TZVP, CPCM(CH2Cl2)	H2O and MeOH are nearly identical; imidazole slightly blue-shifts Qx and the B-band pair while leaving Qy almost unchanged.
009	Mg-chlorin axial ligation	Mg-chlorin with H2O, MeOH, imidazole	Full TD-DFT, def2-TZVP, CPCM(CH2Cl2)	H2O and MeOH are nearly identical; imidazole lowers S1, S2, and both bright B-region states.
010	Chlorophyllide growth	Chlorin, minimal Mg-phorbine, chlorophyllide a	B3LYP-D4 geometries; full TD-DFT/def2-TZVP, gas phase and CPCM(CH2Cl2)	Peripheral substitution red-shifts Qy and Bx across the hybrids; TPSS fragments the B-state manifold.
011	Chlorophyll a phytol-truncation test	Chlorophyllide a and chlorophyll a	B3LYP-D4 geometries; full TD-DFT/def2-TZVP, CPCM(CH2Cl2)	Phytol attachment shifts Qy, Qx, Bx, and By by less than 2 meV across all five functionals.
012	Bacteriochlorophyllide a growth	Mg-bacteriochlorin and bacteriochlorophyllide a	B3LYP-D4 geometries; full TD-DFT/def2-TZVP, CPCM(CH2Cl2)	Ring-E and peripheral growth strongly red-shift the spectrum and fragment the B-state manifold, especially with TPSS.
013	Bacteriochlorophyll a phytol-truncation test	Bacteriochlorophyllide a and bacteriochlorophyll a	B3LYP-D4 geometries; full TD-DFT/def2-TZVP, CPCM(CH2Cl2)	Phytol attachment shifts S1 by at most 9.20 meV and S2 by at most 3.82 meV across the five functionals.
014	Chlorophyllide a in acetone against experiment	Chlorophyllide a	Full TD-DFT, def2-TZVP, CPCM(acetone)	After Qy alignment, all five functionals leave the Soret maximum 0.175 to 0.376 eV too high in energy.
015	Bacteriochlorophyll phytyl effect in DMF against experiment	Bacteriochlorophyll a and bacteriochlorophyllide a	Full TD-DFT, def2-TZVP, CPCM(DMF)	Most functionals reproduce the experimental B-region blue-shift tendency; Q-band details remain limited by missing vibrational structure.

Repository Policy

The .out files are kept because they contain the exact ORCA input block, software version, timings, and other details. Heavy files such as .gbw, .cis, .densities, and related artifacts are intentionally ignored.