An analysis of aligned nematic liquid crystal cells containing core-shell nanospheres shows that it is possible to devise a new type metamaterial whose index refraction tunable from negative, through zero, positive values. The design parameters for the constituents can be scaled application in optical as well very long wavelength (e.g., terahertz and microwave) regions.

We utilize the properties of aligned nematic liquid crystal (LC) cells in design of: (i) a new type metamaterial whose index refraction is tunable from negative, through zero, to positive values and (ii) micron-scale metallodielectric all-dielectric frequency selective surfaces (FSSs). The constructed by randomly doping substrate with coated dielectric (non-magnetic) spheres can be utilized over large spectral range. FSSs superstrate are synthesized using conventional genetic algorithm...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElementary Reaction Mechanism for Growth of Diamond (100) Surfaces from Methyl RadicalsSergei Skokov, Brian Weiner, and Michael FrenklachCite this: J. Phys. Chem. 1994, 98, 28, 7073–7082Publication Date (Print):July 1, 1994Publication History Published online1 May 2002Published inissue 1 July 1994https://pubs.acs.org/doi/10.1021/j100079a030https://doi.org/10.1021/j100079a030research-articleACS PublicationsRequest reuse permissionsArticle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOn the low-lying states and electronic spectroscopy of iron(II) porphineW. Daniel. Edwards, Brian. Weiner, Michael C. ZernerCite this: J. Am. Chem. Soc. 1986, 108, 9, 2196–2204Publication Date (Print):April 1, 1986Publication History Published online1 May 2002Published inissue 1 April 1986https://pubs.acs.org/doi/10.1021/ja00269a012https://doi.org/10.1021/ja00269a012research-articleACS PublicationsRequest reuse permissionsArticle...

Classical trajectory calculations were employed to study the reaction of acetylene with dimer sites on Si(100) surface at 105 K. Two types potential energy functions combined describe interactions for different regions model surface. A quantum mechanical based semiempirical AM1 Hamiltonian was used between C2H2 and a portion silicon surface, while an empirically parametrized developed extend size simulate dynamics surrounding atoms. Reactions approaching investigated, directly above dimer,...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElementary reaction mechanism of diamond growth from acetyleneSergei Skokov, Brian Weiner, and Michael FrenklachCite this: J. Phys. Chem. 1994, 98, 1, 8–11Publication Date (Print):January 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/j100052a003https://doi.org/10.1021/j100052a003research-articleACS PublicationsRequest reuse permissionsArticle Views151Altmetric-Citations56LEARN...

The generalized antisymmetrized geminal-power (GAGP) function, shown to be the ground state for oneparticle-hole propagator, can computed using rather simple properties of its reduced density matrices and unitary transformations. practical procedure involves limited storage notwithstanding large number configurations with which GAGP function associated. Using stability previously derived this we construct self-consistent one-particle-hole propagator.

Classical trajectory calculations were employed to study diamond (100) surface reconstructions. Atomic forces computed from two types of potential-energy functions. A quantum mechanical potential based on the semiempirical PM3 (parametric method number three) Hamiltonian was used describe central core model, while an empirically parametrized developed extend size model surface. The results indicate that most energetically favorable consists alternating monohydride dimers and dihydride sites....

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe reaction C3H3+ + acetylene and the structural isomers of C5H5+Jikang Feng, Jerzy Leszczynski, Brian Weiner, Michael C. ZernerCite this: J. Am. Chem. Soc. 1989, 111, 13, 4648–4655Publication Date (Print):June 1, 1989Publication History Published online1 May 2002Published inissue 1 June 1989https://pubs.acs.org/doi/10.1021/ja00195a019https://doi.org/10.1021/ja00195a019research-articleACS PublicationsRequest reuse permissionsArticle...

Some of the difficulties encountered in approximation Green's functions are reviewed with particular emphasis on self-consistent polarization propagator. new basic theorems presented, involving a general procedure, which lead to both derivation and alternate prescriptions for computations. As demonstrated by Linderberg Öhrn ground state is an AGP (antisymmetrized geminal power). An energy optimized (EAGP) Brueckner orbital representation can be used generate manifold excited states|K⟩ =...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of Acetylene on Diamond (100) SurfacesSergei Skokov, Brian Weiner, and Michael FrenklachCite this: J. Phys. Chem. 1995, 99, 15, 5616–5625Publication Date (Print):April 1, 1995Publication History Published online1 May 2002Published inissue 1 April 1995https://pubs.acs.org/doi/10.1021/j100015a053https://doi.org/10.1021/j100015a053research-articleACS PublicationsRequest reuse permissionsArticle Views146Altmetric-Citations49LEARN ABOUT THESE...

Abstract We examine a variety of methods for obtaining the stable geometry molecules and transition states simple systems summarize some our findings. find most efficient optimizing structure to be those based on calculated gradients estimated second derivative (Hessian) matrices, later obtained either from Broyden–Fletcher–Goldfarb–Shanno ( BFGS ) quasi‐Newton update method or approximations coupled perturbed Hartree–Fock method. For uncovering we particularly useful augmented Hessian...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic structure and spectra of various spin states (porphinato)iron(III) chlorideW. Daniel Edwards, Brian Weiner, Michael C. ZernerCite this: J. Phys. Chem. 1988, 92, 22, 6188–6197Publication Date (Print):November 1, 1988Publication History Published online1 May 2002Published inissue 1 November 1988https://doi.org/10.1021/j100333a006RIGHTS & PERMISSIONSArticle Views75Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and properties of C3H3+ cationsAlan Cameron, Jerzy Leszczynski, Michael C. Zerner, Brian WeinerCite this: J. Phys. Chem. 1989, 93, 1, 139–144Publication Date (Print):January 1989Publication History Published online1 May 2002Published inissue 1 January 1989https://pubs.acs.org/doi/10.1021/j100338a031https://doi.org/10.1021/j100338a031research-articleACS PublicationsRequest reuse permissionsArticle Views317Altmetric-Citations40LEARN ABOUT...

Classical trajectory calculations were employed to study oxygenated (100) diamond surfaces. Atomic forces computed from two types of potential energy functions, a quantum mechanical based on the semiempirical PM3 (parametric method number 3) Hamiltonian which was used describe central code core surface model and an empirically parametrized that developed extend size surface. The results indicate energetically most favorable structure is bridge oxygen monolayer. However, due effect entropy,...

Quantum ab initio calculations and quantum semiempirical molecular-dynamics simulations were employed to study reconstructions of (100) diamond surfaces in the presence hydrogen oxygen. The results indicate that energetically most favorable structures oxygenated are those with chemisorbed hydroxyl groups. It was found bonds formed among species. formation these lowers adlayer energy. A number important vibrational modes characteristic identified. analysis surface spectra demonstrates...

Abstract A theorem is presented that characterizes approximate states and truncated operator manifolds associated with self‐consistent propagators. This establishes a natural relationship between Hermiticity, stationarity, nonredundance completeness of manifolds, model time evolution, the vacuum condition. For case polarization propagator we describe algorithms by which can construct satisfy this

The nature of the bonding between carbon atoms reconstructed dimers on a dehydrogenated (100)-(2×1) diamond surface is examined. Utilizing complete active space self-consistent field (CASSCF) description and 6-31G** basis set it demonstrated that such dimer units form biradical are not purely π bonded as has often been conjectured. significance these findings for growth mechanisms surfaces involving radical sites discussed.

The theory of vector coherent states is applied to multiconfiguration that are given a complex parametrization, based on the underlying special linear group. Using time-dependent variational principle, equations motion for such formulated as evolution in generalized phase space. classical Hamiltonian these terms reduced first- and second-order density matrices, which can be expressed partial derivatives with respect group parameters overlap kernel. self-consistent-field (MCSCF) configuration...

A consistent approximation to the polarization propagator is developed and compared others viz Tamm–Dancoff random phase approximations (TDA RPA, respectively). The role of a properly defined vacuum as reference state for examined. It shown that closest one can come ‘‘consistent RPA’’ generalized TDA which corresponds based on an energy optimized antisymmetrized geminal power (GAGP) state. theory applied nitrogen molecule in slightly simplified form calculated excited electronic states are...

The interaction between the acetylene molecule and Si(111) surface was modeled using geometry optimization pathway of Zerner intermediate neglect differential overlap semiempirical quantum chemical program. represented by a 49-atom cluster containing four layers silicon atoms. To determine effect upon surface, 12 central atoms from top two were allowed to move stable positions. initially optimized without acetylene, resulting in significant rearrangement mobile Nine separate calculations...

Various expressions for antisymmetrized geminal-power (AGP) states are reviewed. With the use of a simple relationship creation and annihilation operators BCS (Bardeen, Cooper, Schrieffer)-type states, such characterized AGP GAGP (generalized AGP) schemes. The effect degeneracy in first-order reduced density matrix on these is displayed.

The Kohn–Sham (KS) procedure for variational minimization of the Hohenberg–Kohn density functional utilizes a one-particle reduced matrix assumed diagonal form, hence depends implicitly on set auxiliary states. Originally, state was to be single determinant with doubly occupied spin orbitals, i.e., same form as in “restricted” Hartree–Fock theory. pragmatic and formal extension KS noninteger occupation numbers requires more general forms or even its replacement by an ensemble. Though...