In previous work we presented Functional Reactive Programming (FRP), a general framework for designing hybrid systems and developing domain-specific languages for related domains. FRP’s synchronous dataflow features, like event driven switching, supported by higherorder lazy functional abstractions of Haskell allows rapid development of modular and reusable specifications. In this paper, we wil...

Representative atomic and molecular systems, including various inorganic and organic molecules with covalent and ionic bonds, have been studied by using density functional theory. The calculations were done with the commonly used exchange-correlation functional B3LYP followed by a comprehensive analysis of the calculated highest-occupied and lowest-unoccupied Kohn-Sham orbital (HOMO and LUMO) e...

Unrestricted density functional theory (UDFT) can be used for the description of open-shell singlet (OSS) biradicals provided a number of precautions are considered. Biradicals that require a two-determinantal wave function (e.g. OSS state of carbenes) cannot be described by UDFT for principal reasons. However, if the overlap between the open-shell orbitals is small (the single electrons are lo...

The vibrational frequencies and molecular geometry of the title compound are examined theoretically using the density functional theory (DFT) B1LYP, B3LYP, B3P86 and B3PW91 methods. For vibrational frequencies, the correlation coefficients obtained for B1LYP, B3LYP, B3P86, and B3PW91 methods are 0.998, 0.999, 0.998 and 0.998, respectively. B3LYP method provides most satisfactory correlation (CC...

Large-scale density functional theory calculations (DFT) found various types of binding of an unsaturated hydrocarbon (C2H2 and C2H4) to a ZSM-5 zeolite extraframework copper cation. We employed the DFT calculations based on the B3LYP functional to obtain local minima of an unsaturated hydrocarbon adsorbed on one or two copper cations embedded inside ZSM-5, and then compared their stabilization...

Using density functional theory (DFT) with gradient-corrected exchange-correlation functionals (B3LYP), we systematically study the electronic structure and bonding of oxygen to various Pt-clusters. Our aim is to understand how the cluster size and shape affect the chemistry of dispersed catalysts and to find the smallest cluster suitable for modeling surface reactions on the Pt(111)-surface. W...

Ab initio density functional theory, using the B3LYP hybrid functional with all-electron basis sets, has been applied to the adsorption of H on the (0001) surface of wurtzite GaN. For bulk GaN, good agreement is obtained with photoemission and X-ray emission data for the valence band and for the Ga 3d and N 2s shallow core levels. A band gap of Eg = 4.14 eV is computed vs the experimental value...

We present recent theoretical results for the V3 and Au4 clusters. Calculations of the V3 doublet system indicate that the 6-311+G(d) basis set is sufficiently flexible to provide reliable minimum energy structures and vibrational frequencies, that these structures and frequencies are insensitive to spin contamination of the wave function when the BPW91 functional is used, and that changing to ...

The natural optical activity of two chiral amino acids, alanine and proline, has been calculated using HartreeFock and density-functional theory with the Becke three-parameter Lee-Yang-Parr (B3LYP) functional employing analytical response theory. The dependence of the optical activity on the molecular conformation in the gas phase was investigated. In the case of proline, calculations were also...

We present a noniterative method to calculate spin-orbit coupling by means of a theoretical approach that provides the use of the full Breit-Pauli operator. This method was applied to compute one and two-electron spin-orbit coupling contributions between singlet and triplet, and doublet and doublet states, respectively. These states have been represented by monodeterminantal wave functions and ...