Benchmark datasets for crystalline organic semiconductors

Notations

The database is grouped in folders, each folder corresponding to a single polymorph encoded in the folder name as system_polymorph, where 'system' is the name of the material and 'polymorph' is the polymorph label, e.g. 'cryst-b' is beta-polymorph, 'cryst-aH' is high-symmetry/temperature alpha-polymorph, 'cryst-x' is purely computational polymorph, 'cryst' is the main polymorph and so forth. Each folder contains the following files:

• polymoprh_method.xyz geometry optimized/obtained by 'method' in XYZ-format (see method notations, 'exp' means experimental data)
• polymoprh_method_cif.cif CIF-version of geometry for visualization only (less complete that XYZ-file)
• polymoprh_method.out single point calculation of energy with fine k-grid
• polymoprh_method_sp.out single point calculation of energy with the same k-grid as in geometry optimization
• polymoprh_method_freq.out calculation of vibrational modes at Gamma-point (due to large size these files are available per request)
• polymoprh_method_freq.txt brief analysis of the above file
• polymoprh_method_vs.pdf volume scan and equation of state parameters in graphical format
• polymoprh_method_vs.txt volume scan and equation of state parameters in text format
• molec_method.xyz geometry of an isolated molecule optimized by 'method' in XYZ-format
• molec_method.out single point calculation of total energy of an isolated molecule
• molec_method_esp.out atomic charges (ESP, CM5, Hirshfeld)

Computational methodology

All calculations and data processing are performed with the same set of computational protocols referenced below:

• Molecular crystal CIF refinement
• Molecular crystal geometry optimization (initial geometry is usually the experimental one)

Selection of materials

Datasets are composed and will be refined in future according to the following principles:

• All included materials have a well defined 'main' polymorph known either experimentally (in most of the cases) or obtained by comprehensive computational search. Here "well defined" means that different accurate approaches (including experiment) converge to the same structure.
• All crystals are dynamically stable except for a few higher energy polymorphs either with small imaginary frequencies or important for some reasons (e.g. structural prototypes). For crystals with large unit cell vibrational frequencies are not calculated.
• Majority of datasets are limited to elements of the first three periods. Some datasets involve elements of the 4th period, e.g. transition metals. Heavier elements are avoided.

Datasets

All data are 7-zipped into one archive per method (here is PBE-D3paw600), below are indexes to datasets as text files whose first line contains coma-separated list of entries, and the rest of file provides some technical description of the dataset (there 'na' is number of atoms in unit cell, 'na1' is number of atoms in molecule, 'Ebind' binding energy in eV per molecule, 'freq' are imaginary frequencies, 'missing' lists missing files). Because for isolated molecules much more complicated calculations can be performed in a basis of atomic orbitals, we have added single-molecule calculations (here is CAM-B3LYPp2p).

• Main polymorph of single-conformer molecules [23.01.2023, 57 molecules, table, index]: acenes, oligothiophenes, PAHs, azaacenes, thienoacenes, imides, quinones, indigos, and other core systems including TCNQs, stilbene, TTF, C60
• [To be uploaded soon] Polymorphs
• [To be uploaded soon] Multi-conformer molecules with side chains + crystalline sidechains
• [Not too many, to be uploaded later] Polymers
• [Not too many, to be uploaded later] Metal-organics