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The counterpoise (CP) correction by Boys and Bernardi has been well accepted as a reliable strategy to account for basis set superposition error (BSSE) in intermolecular complexes. The behavior of the CP correction was thoroughly studied in individual molecules of molecular complexes. This work studies the performance of the CP correction in many‐body clusters including three‐body clusters of organic compounds in the 3B‐69 dataset. Additionally, we used crystal structures of polymorphs of benzene, aspirin, and oxalyl dihydrazide (ODH) to construct a many‐body cluster dataset, abbreviated as the MBC‐36 dataset, consisting of two, four and eight molecules, and 16 molecules in the case of benzene. A series of Dunning's basis sets—cc‐pXZ and aug‐cc‐pXZ (X = D and T)—were used to predict CP‐corrected Hartree–Fock (HF) interaction energies of the 3B‐69 and MBC‐36 datasets. The CP‐corrected interaction energies were found to be basis‐set independent, whereas the non‐CP corrected interaction energies were found not to a follow a smooth exponential fitting as previously found for electronic energies of individual molecules. This observation was attributed to the presence of non‐additive induction forces in some clusters. Two 2 × 2 × 2 supercells of benzene polymorphs were constructed to explore the local nature of BSSE effects. A cut‐off radius of 10 Å was demonstrated to be sufficient to fully recover these effects. Although the behavior of CP correction was found to be non‐conventional in many‐body clusters of organic compounds, the use of a small basis set such as cc‐pVDZ showed excellent performance in the prediction of HF interaction energies. [ABSTRACT FROM AUTHOR]

We present an inexpensive and robust theoretical approach based on the fragment molecular orbital methodology and the spin‐ratio scaled second‐order Møller–Plesset perturbation theory to predict the lattice energy of benzene crystals within 2 kJ⋅mol−1. Inspired by the Harrison method to estimate the Madelung constant, the proposed approach calculates the lattice energy as a sum of two‐ and three‐body interaction energies between a reference molecule and the surrounding molecules arranged in a sphere. The lattice energy converges rapidly at a radius of 13 Å. Adding the corrections to account for a higher correlated level of theory and basis set superposition for the Hartree Fock (HF) level produced a lattice energy of −57.5 kJ⋅mol−1 for the benzene crystal structure at 138 K. This estimate is within 1.6 kJ⋅mol−1 off the best theoretical prediction of −55.9 kJ⋅mol−1. We applied this approach to calculate lattice energies of the crystal structures of phase I and phase II—polymorphs of benzene—observed at a higher temperature of 295 K. The stability of these polymorphs was correctly predicted, with phase II being energetically preferred by 3.7 kJ⋅mol−1 over phase I. The proposed approach gives a tremendous potential to predict stability of other molecular crystal polymorphs. [ABSTRACT FROM AUTHOR]

Many hospitals in developing countries, including Vietnam, are facing the challenges of increasingly noncommunicable diseases and the financial autonomy policy from the government. To adapt to this new context requires understanding and changing the current organisational culture of the hospitals. However, little has been known about this in resource-constrained healthcare settings. The objectives of this study were to examine the four characteristics of the organisational culture and test selected individual and occupational differences in the organisational culture of a Vietnam central hospital. In a cross-sectional study using the Organisation Culture Assessment Instrument (OCAI) with the Competing Value Framework (CVF), including 4 factors, Clan, Adhocracy, Hierarchy, and Market, health workers currently working at Quang Nam General Hospital were interviewed. The results indicated the current cultural model was more internally focused with two dominant cultures, Clan and Hierarchy, while, for the desired model, the Clan culture was the most expected one. Comparing between the current and desired pattern, the down trend was found for all types of culture, except the Clan culture, and there were significant differences by domains of organisational culture. Furthermore, the current and desired models were differently distributed by key individual characteristics. These differences have raised a number of interesting directions for future research. They also suggest that, to build a hospital organisational culture to suit both current and future contexts as per employees' assessment and expectation, it is important to take individual and institutional variations into account. [ABSTRACT FROM AUTHOR]