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Related papers: The empirical equilibrium structure of diacetylene

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This work studies the symmetries, the associated momentum map, and relative equilibria of a mechanical system consisting of a small axisymmetric magnetic body-dipole in an also axisymmetric external magnetic field that additionally exhibits…

Symplectic Geometry · Mathematics 2013-11-12 Lyudmila Grigoryeva , Juan-Pablo Ortega , Stanislav Zub

Equilibrium polyethylene crystal structure, cohesive energy, and elastic constants are calculated by density-functional theory applied with a recently proposed density functional (vdW-DF) for general geometries [Phys. Rev. Lett. 92, 246401…

Materials Science · Physics 2009-11-11 Jesper Kleis , Bengt I. Lundqvist , David C. Langreth , Elsebeth Schroder

Alchemical perturbation density functional theory has been shown to be an efficient and computationally inexpensive way to explore chemical compound space. We investigate approximations made, in terms of atomic basis sets and perturbation…

Chemical Physics · Physics 2020-10-28 Giorgio Domenichini , Guido Falk von Rudorff , O. Anatole von Lilienfeld

Vibrational properties of molecules are of widespread interest and importance in chemistry and biochemistry. The reliability of widely employed approximate computational methods is questioned here against the complex experimental spectrum…

Chemical Physics · Physics 2025-09-24 Apurba Nandi , Riccardo Conte , Priyanka Pandey , Paul L. Houston , Chen Qu , Qi Yu , Joel M. Bowman

Using APEX-1 and APEX-2 observations, we have detected and studied the rotational lines of the HC$_3$N molecule (cyanoacetylene) in the powerful outflow/hot molecular core G331.512-0.103. We identified thirty-one rotational lines at $J$…

The paper introduces a simple quantum model to calculate in a general way allowed frequencies and energy levels of the anharmonic oscillator. The theoretical basis of the approach has been introduced in two early papers aimed to infer the…

Quantum Physics · Physics 2011-05-19 Sebastiano Tosto

We investigate equilibrium microstructures exhibited by diblock copolymers in confined 3D geometries. We perform Self-Consistent Field Theory (SCFT) simulations using a finite-element based computational framework (Ackerman et al. 2017),…

Soft Condensed Matter · Physics 2019-10-22 Ananth Tenneti , David M Ackerman , Baskar Ganapathysubramanian

Background: The isotropic harmonic oscillator supplemented by a strong spin-orbit interaction has been the cornerstone of nuclear structure since its inception more than seven decades ago. In this paper we introduce---or rather…

Nuclear Theory · Physics 2020-11-11 Junjie Yang , J. Piekarewicz

Electroexcitations of the dominantly T=1 particle-hole states of C-12 are studied in the framework of the harmonic oscillator shell model. All possible T=1 single-particle-hole states of all allowed angular momenta are considered in a basis…

Nuclear Theory · Physics 2009-09-29 F. A. Majeed , R. A. Radhi

We consider a well-known static, axially symmetric, vacuum solution of Einstein equations belonging to Weyl's class and determine the fundamental frequencies of small harmonic oscillations of test particles around stable circular orbits in…

General Relativity and Quantum Cosmology · Physics 2019-08-05 Bobir Toshmatov , Daniele Malafarina , Naresh Dadhich

The conformational space of the dimyristoyl phosphatidylcholine (DMPC) molecule has been studied using Density Functional Theory (DFT), augmented with a damped empirical dispersion energy term (DFT-D). Fourteen ground-state isomers have…

Other Condensed Matter · Physics 2008-06-05 S. Krishnamurty , M. Stefanov , T. Mineva , S. Begu , J. M. Devoisselle , A. Goursot , R. Zhu , D. R. Salahub

The self-consistent harmonic approximation is an effective harmonic theory to calculate the free energy of systems with strongly anharmonic atomic vibrations, and its stochastic implementation has proved to be an efficient method to study,…

Materials Science · Physics 2017-07-26 Raffaello Bianco , Ion Errea , Lorenzo Paulatto , Matteo Calandra , Francesco Mauri

We present fully numerical electronic structure calculations on diatomic molecules exposed to an external magnetic field at the unrestricted Hartree-Fock limit, using a modified version of a recently developed finite element program,…

Chemical Physics · Physics 2020-02-12 Susi Lehtola , Maria Dimitrova , Dage Sundholm

In this paper, we investigate periodic vibrations of a group of particles with a dihedral configuration in the plane governed by the Lennard-Jones and Coulomb forces. Using the gradient equivariant degree, we provide a full topological…

Dynamical Systems · Mathematics 2017-02-15 Irina Berezovik , Qingwen Hu , Wieslaw Krawcewicz

We report the experimental implementation of the Dicke model in the semiclassical approximation, which describes a large number of two-level atoms interacting with a single-mode electromagnetic field in a perfectly reflecting cavity. This…

A random matrix model to describe the coupling of m-fold symmetry in constructed. The particular threefold case is used to analyze data on eigenfrequencies of elastomechanical vibration of an anisotropic quartz block. It is suggested that…

Data Analysis, Statistics and Probability · Physics 2007-11-18 J. X. Carvalho , M. S. Hussein , M. P. Pato , A. J. Sargeant

The fundamental ground tone vibration of H2, HD, and D2 is determined to an accuracy of 2 x 10^-4 cm^-1 from Doppler-free laser spectroscopy in the collisionless environment of a molecular beam. This rotationless vibrational splitting is…

DFT(B3LYP, B3PW91) level calculations in conjunction with three different of basis sets have been used to investigate the variations in the bond lengths, dipole moment and rotational constants, IR frequencies, IR intensities and rotational…

Chemical Physics · Physics 2007-05-23 Pradeep Risikrishna Varadwaj

We investigate the critical dynamics of the $n$-component relaxational models C and D which incorporate the coupling of a nonconserved and conserved order parameter S, respectively, to the conserved energy density rho, under nonequilibrium…

Statistical Mechanics · Physics 2009-11-10 Vamsi K. Akkineni , Uwe C. Tauber

We experimentally probe electron collisions with HC$_3$N in the energy range from 0 to 10 eV with the focus on vibrational excitation and dissociative electron attachment. The vibrational excitation cross sections show a number of…

Chemical Physics · Physics 2018-12-04 M. Ranković , P. Nag , M. Zawadzki , L. Ballauf , J. Žabka , M. Polášek , J. Kočišek , J. Fedor