Search results for "Orbit"

Origin invariant calculation of optical rotation without recourse to London orbitals

2004

We propose an inherently origin invariant formulation of specific optical rotation obtained from the conventional velocity gauge expression by subtracting the static limit from the electric dipole-magnetic dipole polarizability: 〈〈p→,L→〉〉ω→〈〈p→,L→〉〉ω-〈〈p→,L→〉〉0. London (gauge including) atomic orbitals are therefore not needed to ensure origin invariance and, consequently, this modified velocity gauge formulation may be employed in conjunction with variational and non-variational quantum chemical methods alike. Sample calculations on S-propylene oxide and 3,4- methylenedioxymethamphetamine using self-consistent field and coupled cluster wave functions…

A new radiation infrastructure for the Modular Earth Submodel System (MESSy, based on version 2.51)

2016

Abstract. The Modular Earth Submodel System (MESSy) provides an interface to couple submodels to a basemodel via a highly flexible data management facility (Jöckel et al., 2010). In the present paper we present the four new radiation related submodels RAD, AEROPT, CLOUDOPT and ORBIT. The submodel RAD (with shortwave radiation scheme RAD_FUBRAD) simulates the radiative transfer, the submodel AEROPT calculates the aerosol optical properties, the submodel CLOUDOPT calculates the cloud optical properties, and the submodel ORBIT is responsible for Earth orbit calculations. These submodels are coupled via the standard MESSy infrastructure and are largely based on the original radiation scheme of …

The HADES RV Programme with HARPS-N@TNG VIII. Gl15A: A multiple wide planetary system sculpted by binary interaction

2018

We present 20 years of radial velocity (RV) measurements of the M1 dwarf Gl15A, combining 5 years of intensive RV monitoring with the HARPS-N spectrograph with 15 years of archival HIRES/Keck RV data. We carry out an MCMC-based analysis of the RV time series, inclusive of Gaussian Process (GP) approach to the description of stellar activity induced RV variations. Our analysis confirms the Keplerian nature and refines the orbital solution for the 11.44-day period super Earth, Gl15A\,b, reducing its amplitude to $1.68^{+0.17}_{-0.18}$ m s$^{-1}$ ($M \sin i = 3.03^{+0.46}_{-0.44}$ M$_\oplus$), and successfully models a long-term trend in the combined RV dataset in terms of a Keplerian orbit wi…

A semi-classical derivation of the spin-orbit electromagnetic interaction

1973

Erratum to: A semi-classical derivation of the spin-orbit electromagnetic interaction

1973

Giant Negative Magnetoresistance Driven by Spin-Orbit Coupling at theLaAlO3/SrTiO3Interface

2015

The LaAlO3=SrTiO3 interface hosts a two-dimensional electron system that is unusually sensitive to the application of an in-plane magnetic field. Low-temperature experiments have revealed a giant negative magnetoresistance (dropping by 70%), attributed to a magnetic-field induced transition between interacting phases of conduction electrons with Kondo-screened magnetic impurities. Here we report on experiments over a broad temperature range, showing the persistence of the magnetoresistance up to the 20 K range—indicative of a single-particle mechanism. Motivated by a striking correspondence between the temperature and carrier density dependence of our magnetoresistance measurements we propo…

Analytic gradients for the state-specific multireference coupled cluster singles and doubles model.

2009

The general theory of analytic energy gradients is presented for the state-specific multireference coupled cluster method introduced by Mukherjee and co-workers [Mol. Phys. 94, 157 (1998)], together with an implementation within the singles and doubles approximation, restricted to two closed-shell determinants and Hartree-Fock orbitals. Expressions for the energy gradient are derived based on a Lagrangian formalism and cast in a density-matrix notation suitable for implementation in standard quantum-chemical program packages. In the present implementation, we exploit a decomposition of the multireference coupled cluster gradient expressions, i.e., lambda equations and the corresponding dens…

Interpretation of unexpected behavior of infrared absorption spectra ofScF3beyond the quasiharmonic approximation

2016

Scandium fluoride (${\mathrm{ScF}}_{3}$), having cubic ${\mathrm{ReO}}_{3}$-type structure, has attracted much scientific attention due to its rather strong negative thermal expansion (NTE) in the broad temperature range from 10 to 1100 K. Here we use the results of diffraction and extended x-ray absorption fine-structure (EXAFS) spectroscopy to interpret the influence of NTE on the temperature dependence of infrared absorption spectra of ${\mathrm{ScF}}_{3}$. Original infrared absorption and EXAFS experiments in a large temperature range are presented and interpreted using ab initio lattice dynamics simulations within and beyond quasiharmonic approximations. We demonstrate that ab initio e…

A multispacecraft analysis of a small-scale transient entrained by solar wind streams

2009

The images taken by the Heliospheric Imagers (HIs), part of the SECCHI imaging package onboard the pair of STEREO spacecraft, provide information on the radial and latitudinal evolution of the plasma compressed inside corotating interaction regions (CIRs). A plasma density wave imaged by the HI instrument onboard STEREO-B was found to propagate towards STEREO-A, enabling a comparison between simultaneous remote-sensing and in situ observations of its structure to be performed. In situ measurements made by STEREO-A show that the plasma density wave is associated with the passage of a CIR. The magnetic field compressed after the CIR stream interface (SI) is found to have a planar distribution…

Spin-orbit interaction in bremsstrahlung and its effect on the electron motion in a strong Coulomb field

2015

Linear polarization of bremsstrahlung x rays produced in collisions of longitudinally polarized 2.1-MeV electrons with gold atoms was studied using the Compton scattering technique. We observed that the angle of x-ray polarization is strongly correlated with the incoming electron polarization. This correlation reveals the dominance of the spin-orbit interaction in bremsstrahlung and indicates a striking effect of the electron spin on the electron motion in a strong Coulomb field. The results confirm the validity of the theoretical predictions in a computationally challenging energy regime.