A model for estimation of activity for efavirenz analogues with the K 103N mutant of HIV-1 RT was proposedin this work. The new model is predictive that requires only variable connectivity indices in the calculations. Compared with the existing models based on Monte Carlo simulation, the new model is easier to apply with better predictive accuracy, giving an r2 of 0.85, cross-validated Q2 of 0.82 and average error of only 0.23kcal/mol for the 47 efavirenz analogues concerned. This work also demonstrates that variable connectivity indices, a class of not widely recognizedstructural descriptors, are quite useful in the QSAR studies in the fields of pharmaceutics and biochemistry. These topological indices may play a more important role in these fields in future.

The BeHeþn clusters with n=1-12 were investigated by ab initio calculations at the level of MP2 (full)/6-311+G (2d, 2p). All the most stable geometric structures were obtained. It is found that the first solvation shell around the beryllium ion core is completed at n=12, and the mechanism of cluster forming can be explained in terms of the solvated ion core model. The effects of basis set superposition error (BSSE) correction and zero-point vibrational energy (ZPE) correction to the energies were considered in the calculations.

Based on White s renormalization group (RG) theory and the statistical associating fluid theory, a new equation of state (EOS) is derived, which can be used for a variety of fluids, including non-polar, polar and associating chain fluids both inside and outside the critical region. The new EOS, with the advantage of not introducing any additional adjustable parameter to the RG transform for real fluids, yields satisfactory critical exponent, vapor-liquid coexistence densities and vapor pressures, pVT isotherms, and isobaric specific heats for pure fluids. Especially, much better results are obtained than the original EOS in the nearest vicinity of the critical point.

The SAFT equation of state (EOS) combined with a one-parameter mixing rule was used to evaluate the capability of the SAFT approach for modeling the solubility of solid aromatic compounds in supercritical fluids (SCFs) with cosolvents. Binary interaction parameters were obtained by fitting the phase equilibrium data of the constituent binary systems. The SAFT EOS was used to predict the solubility of solids in carbon dioxide with cosolvents for five systems, and the overall average absolute relative deviation (AARD) was 20.43%. For the other 11 systems, the binary interaction parameters between the solids and the cosolvents were obtained by fitting the ternary solubility data, and the overall AARD was 16.45%. Comparison with the PRSV EOS showed that the SAFT EOS was superior in terms of both prediction and correlation. The present work demonstrates that the SAFT approach is useful for modeling the solubility of solids in SCFs with cosolvents with reasonable accuracy.

Metal-organic frameworks (MOFs) are thought to be a set of promising hydrogen storage materials; however, little is known about the interactions between hydrogen molecules and pore walls as well as the diffusivities of hydrogen in MOFs. In this work, we performed a systematic molecular simulation study on the adsorption and diffusion of hydrogen in MOFs to provide insight into molecular-level details of the underlying mechanisms. This work shows that metal-oxygen clusters are preferential adsorption sites for hydrogen in MOFs, and the effect of the organic linkers becomes evident with increasing pressure. The hydrogen storage capacity of MOFs is similar to carbon nanotubes, which is higher than zeolites. Diffusion of hydrogen in MOFs is an activated process that is similar to diffusion in zeolites. The information derived in this work is useful to guide the future rational design and synthesis of tailored MOF materials with improved hydrogen adsorption capability.