Search results for "molecular system"
showing 10 items of 44 documents
Development of non-equilibrium Green's functions for use with full interaction in complex systems
2016
We present an ongoing development of an existing code for calculating groundstate, steady-state, and transient properties of many-particle systems. The development involves the addition of the full four-index two electron integrals, which allows for the calculation of transport systems, as well as the extension to multi-level electronic systems, such as atomic and molecular systems and other applications. The necessary derivations are shown, along with some preliminary results and a summary of future plans for the code. peerReviewed
Out‐of‐Equilibrium (Supra)molecular Systems and Materials: An Introduction
2021
A two-scale approach to electron correlation in multiconfigurational perturbation theory.
2014
We present a new approach for the calculation of dynamic electron correlation effects in large molecular systems using multiconfigurational second-order perturbation theory (CASPT2). The method is restricted to cases where partitioning of the molecular system into an active site and an environment is meaningful. Only dynamic correlation effects derived from orbitals extending over the active site are included at the CASPT2 level of theory, whereas the correlation effects of the environment are retrieved at lower computational costs. For sufficiently large systems, the small errors introduced by this approximation are contrasted by the substantial savings in both storage and computational de…
Genetic and Ecotypic Differentiation in a Californian Plant Polyploid Complex (Grindelia, Asteraceae)
2014
Studies of ecotypic differentiation in the California Floristic Province have contributed greatly to plant evolutionary biology since the pioneering work of Clausen, Keck, and Hiesey. The extent of gene flow and genetic differentiation across interfertile ecotypes that span major habitats in the California Floristic Province is understudied, however, and is important for understanding the prospects for local adaptation to evolve or persist in the face of potential gene flow across populations in different ecological settings. We used microsatellite data to examine local differentiation in one of these lineages, the Pacific Coast polyploid complex of the plant genus Grindelia (Asteraceae). W…
Quantum chemistry of the excited state: 2005 overview
2005
The present contribution contains an overview of quantum-chemical methods and strategies to compute and interpret spectroscopic and photochemical phenomena in molecular systems. The state of the art for the quantum chemistry of the excited state is reviewed, focusing in the advantages and disadvantages of the most commonly employed computational methods, from the single configurational procedures like CI-Singles (CIS), propagator approaches, and Coupled-Cluster (CC) techniques, to the more sophisticated multiconfigurational treatments, with particular emphasis on perturbation theory, the CASPT2 approach. Also, a short summary on the performance, lights, and shadows of the popular TDDFT meth…
Quantum computing with molecular spin systems
2009
Molecular spintronics promises to combine the flexibility offered by synthetic chemistry with the advantages of an electronics which is based on the electron spin rather than its charge degree of freedom. Here, we review recent work on the description of transport across molecular spin systems and on a proposal for an all-electrical scheme for the implementation of a fundamental two-qubit gate in a certain class of molecular systems.
Why Bring Organic and Molecular Electronics to Spintronics
2015
Organic spintronics field is an emerging field at the frontier between organic chemistry and spintronics. Exploiting the peculiarity of these two fields, it combines the flexibility, versatility and low production cost of organic materials with the nonvolatility, spin degree of freedom and beyond CMOS capabilities offered by spintronics. Before starting the discussion on the organic spintronics field, in this chapter will be provided a brief introduction on organic and molecular electronics and the specificities of molecules. This will help to understand the advantages that molecular systems can bring to spintronics.
Molecular evidence for the presence of cryptic evolutionary lineages in the freshwater copepod genus Hemidiaptomus G.O. Sars, 1903 (Calanoida, Diapto…
2010
The pattern of morphological and mtDNA cytochrome b diversity of three calanoid copepod species belonging to the diaptomid genus Hemidiaptomus has been investigated with the aim of checking the reliability of the morphological characters currently used for species identification, and the possible presence of cryptic taxa. A sharply different molecular structuring has been observed in the studied species: while Hemidiaptomus amblyodon exhibits a remarkable constancy throughout the European range of its distribution area (maximum inter-populations cytochrome b divergence of 3%), observed distances between presumed conspecific lineages of Hemidiaptomus gurneyi (maximum divergence of 21.5%) and…
Porphyrin and phthalocyanine photosensitizers designed for targeted photodynamic therapy of colorectal cancer
2020
Colorectal cancer is of particular concern due to its high mortality rate count. Recent investigations on targeted phototherapy involving novel photosensitizers and drug-delivery systems have provided promising results and realistic prospects for a successful medical treatment. New research trends have been focused particularly on development of advanced molecular systems offering effective photoactive species which could be selectively delivered directly into the affected cells. Porphyrins and phthalocyanines have been considered extremely attractive for this purpose due to their molecular versatility, excellent photochemical properties and multifunctional nature. In this review it has bee…
A Chiral, Photoluminescent, and Spin-Canted {Cu(I)Re(IV)2}n Branched Chain.
2015
A new heteroleptic 1D Cu(I)-Re(IV) coordination polymer of the formula {Cu(I)Re(IV)Cl4(μ-Cl)(μ-pyz)[Re(IV)Cl4(μ-bpym)]}n·nMeNO2 (1; pyz = pyrazine, bpym = 2,2'-bipyrimidine) has been prepared through the Cu(I)-mediated self-assembly of two different Re(IV) metalloligands, namely, [ReCl5(pyz)](-) and [ReCl4(bpym)]. 1 consists of chiral branched chains with an overall rack-type architecture displaying photoemission and magnetic ordering. These results constitute a first step toward making new multifunctional magnetic materials based on mixed 3d-5d molecular systems.