Accurate Lattice Energies for Molecular Crystals from Experimental Crystal Structures

Abstract

Using four different benchmark sets of molecular crystals, we establish the level of confidence for lattice energies estimated using CE-B3LYP model energies and experimental crystal structures. [ IUCrJ 2017 , 4 , 575 - 587 10.1107/S205225251700848X .] We conclude that they compare very well with available benchmark estimates derived from sublimation enthalpies, and in many cases they are comparable with, and sometimes better than, more computationally demanding approaches, such as those based on periodic DFT plus dispersion methodologies. The performance over the complete set of 110 crystals indicates a mean absolute deviation from benchmark energies of only 6.6 kJ mol. Applications to polymorphic crystals and larger molecules are also presented and critically discussed. The results highlight the importance of recognizing the consequences of different sets of crystal/molecule geometries when different methodologies are compared, as well as the need for more extensive benchmark sets of crystal structures and associated lattice energies.

Exploring the Polymorphism of Drostanolone Propionate

“…Accordingly, the lattice total energies and their dispersion parts computed for the three unit cell configurations with the above described calculation scheme are presented in Table 5b. Comparing the results obtained based on the CLP model [38,39] and by SCC-DFTB theory, relatively good agreement between the two theories can be found for the lattice energy values. This agreement looks effective for the case of Drost 2 crystal configuration (the energy difference is 7.5 kJ/mol), while, for the Drost 1 and Drost 3, the energy deviations are a bit larger: 13.7 and 13.9 kJ/mol, respectively.…”

Solving the enigma of weak fluorine contacts in the solid state: a periodic DFT study of fluorinated organic crystals

“…Other methods from this group used in present work include the Coulomb-London-Pauli scheme developed by Gavezzotti in AA-CLP 79 and PIXEL 80 versions, as well as CE-B3LYP approach. 81 In all three methods, the energy of each pair interaction is calculated as a sum of four terms (coulombic, polarization, dispersion and repulsion). While AA-CLP uses predened force eld parameters for different atom types, PIXEL and CE-B3LYP use molecular wavefunctions and orbitals taken from the gas-phase calculations.…”

“…The PIXEL method, considered to be a more advanced version of AA-CLP, also fails to provide correct lattice energies for CF 4 and C 6 F 5 COOH (Table S5 †). The possible reason for poor performance of PIXEL and CE-B3LYP methods may be caused by the 6-31G** basis set used to estimate the molecular orbital overlap in CE-B3LYP 81 or electron density distribution in the molecule in PIXEL. 80 The basis sets chosen for parameterization of both methods lack diffusion orbital functions, which are essential for the agreement with the experimental distances and sublimation enthalpies (Section 3.1).…”

Structure–property relationships in aromatic thioethers featuring aggregation-induced emission: solid-state structures and theoretical analysis

“…Before starting the calculations, X-H distances were normalized to the values obtained from neutron diffraction studies of small molecules. It has been shown that interaction energies 17 and lattice parameters 18 computed with CrystalExplorer are in excellent agreement with those obtained by means of highly accurate but prohibitively costly wavefunction methods, which were used to prepare the benchmarks reported in 2016. 11…”