The emergent properties that arise from self-assembly and molecular recognition phenomena are a direct consequence of non-covalent interactions. Gas-phase measurements and computational methods point to the dominance of dispersion forces in molecular association, but solvent effects complicate the unambiguous quantification of these forces in solution. Here, we have used synthetic molecular bal...

Article history: Received 7 April 2011 Received in revised form 17 September 2011 Accepted 18 September 2011 Is wind direction an adequate marker of air mass history? This review looks at the evolution of methods for assessing the effect of the origin and pathway of air masses on composition change and trends. The composition of air masses and how they evolve and the changing contribution of so...

We have determined the full magnetic dispersion relations of multiferroic BiFeO3. In particular, two excitation gaps originating from magnetic anisotropies have been clearly observed. The direct observation of the gaps enables us to accurately determine the Dzyaloshinskii-Moriya (DM) interaction and the single ion anisotropy. The DM interaction supports a sizable magnetoelectric coupling in thi...

The objective of present work is to investigate the enhancement of dissolution profile for oral delivery of Fexofenadine Hydrochloride (FH) through solid dispersion (SD) technique by the method of solvent evaporation. The SD was prepared by using ethanol as a solvent. Tablets were formulated containing solid dispersion of FH and compared with tablets of same formula without solid dispersion of ...

The aim of present work was to optimize the effect of Ethyl Cellulose (EC) and Polyvinyl Pyrrolidone (PVP) concentration in extended release solid dispersion of Glibenclamide using combination of hydrophilic and hydrophobic polymers such as Polyvinyl Pyrrolidone and Ethyl cellulose. The advantage of solid dispersion technique provides a unique approach to particle size reduction and increased r...

A method for calculating the dispersion energy between molecules modeled with the general effective fragment potential (EFP2) method and those modeled using a full quantum mechanics (QM) method, e.g., Hartree-Fock (HF) or second-order perturbation theory, is presented. C(6) dispersion coefficients are calculated for pairs of orbitals using dynamic polarizabilities from the EFP2 portion, and dip...

The S66x8 dataset for noncovalent interactions of biochemical relevance has been re-examined by means of MP2-F12 and CCSD(F12*)(T) methods. We deem our revised benchmark data to be reliable to about 0.05 kcal mol(-1) RMS. Most levels of DFT perform quite poorly in the absence of dispersion corrections: somewhat surprisingly, that is even the case for the double hybrids and for dRPA75. Analysis ...

In this work we propose a general strategy to calculate accurate He-surface interaction potentials. It extends the dispersionless density functional approach recently developed by Pernal et al. [Phys. Rev. Lett. 103, 263201 (2009)] to adsorbate-surface interactions by including periodic boundary conditions. We also introduce a scheme to parametrize the dispersion interaction by calculating two-...

First-principles derivation is given for the heuristic exchange-hole model of London dispersion forces by Becke and Johnson [J. Chem. Phys. 122, 154104 (2005)]. A one-term approximation is used for the dynamic charge density response function, and it is shown that a central nonempirical ingredient of the approximate nonexpanded dispersion energy is the charge density autocorrelation function, a...

The accuracy of non-local van der Waals density functional [1] is tested for the thermochemical properties of 1200+ atoms and molecules in the GMTKN30 database. Five (hybrid)GGA functionals are augmented by the non-local (NL) part of the VV10 functional. The widely used atom-pair wise dispersion correction DFT-D3 [2] is considered for comparison. The addition of the NL dispersion energy definit...