Related papers: The relationship between structure and excited-sta…
The HOMO-LUMO gaps of the bilayer fullerene onions were investigated. For this purpose, the HOMO and LUMO energies were calculated for the isolated fullerenes using the parametrization of the tight binding method with the Harrison-Goodwin…
Structural relaxations in electronically excited poly(para-phenylene) are studied using many-body perturbation theory and density-functional-theory methods. A sophisticated description of the electron-hole interaction is required to…
We present density matrix renormalisation group calculations of the Pariser- Parr-Pople-Peierls model of linear polyenes within the adiabatic approximation. We calculate the vertical and relaxed transition energies, and relaxed geometries…
Attachment of chemical substituents (such as polar moieties) constitutes an efficient and convenient way to modify physical and chemical properties of conjugated polymers and oligomers. Associated modifications in the molecular electronic…
Wavefunctions restricted to electron pair states are promising models for strongly-correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and…
Using two different numerical methods, we study the behavior of two-component Fermi gases interacting through short-range s-wave interactions in a harmonic trap. A correlated Gaussian basis-set expansion technique is used to determine the…
We present a theory of a degenerate atomic Fermi gas, interacting through a narrow Feshbach resonance, whose position and therefore strength can be tuned experimentally, as demonstrated recently in ultracold trapped atomic gases. The…
We introduce the electron attachment equation-of-motion pair coupled cluster doubles (EA-EOM-pCCD) ansatz, which allows us to inexpensively compute electron affinities, energies of unoccupied orbitals, and electron attachment spectra. We…
We present semiempirical tight binding calculations on thienylenevinylene oligomers up to the hexadecamer stage (n=16) and ab initio calculations based on the local density approximation up to n=8. The results correctly describe the…
We present a comprehensive theoretical study of the electronic structures of the Yb atom and the Yb$_2$ molecule, respectively, focusing on their ground and lowest-lying electronically excited states. Our study includes various…
The electronic structure of a multichromophoric molecular complex containing two of each borondipyrromethane dye, Zn-tetraphenyl-porphyrin, bisphenyl anthracene and a fullerene are studied using density functional theory. The snowflake…
A precise study within variational approach of the basic properties of the three-particle spectrum and structure functions with Gaussian potential near the critical coupling constant of interaction where the Efimov effect takes place is…
We investigate strongly correlated many-body systems composed of bosons and fermions with a fully quantum treatment using the path-integral ground state method, PIGS. To account for the Fermi-Dirac statistics, we implement the fixed-node…
A systematic method to account for electron correlation in periodic systems which can predict quantitatively correct band structures of non-conducting solids from first principles is presented. Using localized Hartree-Fock orbitals (both…
We demonstrate that, rather than resorting to high-cost dynamic correlation methods, qualitative failures in excited-state potential energy surface predictions can often be remedied at no additional cost by ensuring that optimal molecular…
van der Waals stacking of two-dimensional (2D) materials offers a powerful platform for engineering material interfaces with tailored electronic and optical properties. While most van der Waals multilayers have featured inorganic…
Spatial configurations of randomly charged polymers, known as polyampholytes (PAs), are very sensitive to the overall excess charge Q. Analytical arguments, supported by Monte Carlo simulations and exact enumeration studies, lead to the…
Advanced X-ray spectroscopic techniques are widely recognized as state-of-the-art tools for probing the electronic structure, bonding, and chemical environments of the heaviest elements in the periodic table. In this study, we employ X-ray…
A methodology for constructing a quasi-one-dimensional coupled-resonator phononic metamaterial is presented. This is achieved through the design of artificial phononic analogs of two molecular structures: trans-polyacetylene and…
We performed an extensive first-principles study of nanowires in various pentagonal structures by using pseudopotential plane wave method within the density functional theory. Our results show that nanowires of different types of elements,…