scholarly journals Quantum computation solves a half-century-old enigma: Elusive vibrational states of magnesium dimer found

2020 ◽  
Vol 6 (14) ◽  
pp. eaay4058 ◽  
Author(s):  
Stephen H. Yuwono ◽  
Ilias Magoulas ◽  
Piotr Piecuch
Keyword(s):  
Ground State ◽  
State Of The Art ◽  
Coupled Cluster ◽  
Experimental Investigations ◽  
Experimental Characterization ◽  
Vibrational States ◽  
Vibrational Levels ◽  
State Potential ◽  
Derived Data ◽  
Important System

The high-lying vibrational states of the magnesium dimer (Mg2), which has been recognized as an important system in studies of ultracold and collisional phenomena, have eluded experimental characterization for half a century. Until now, only the first 14 vibrational states of Mg2 have been experimentally resolved, although it has been suggested that the ground-state potential may support five additional levels. Here, we present highly accurate ab initio potential energy curves based on state-of-the-art coupled-cluster and full configuration interaction computations for the ground and excited electronic states involved in the experimental investigations of Mg2. Our ground-state potential unambiguously confirms the existence of 19 vibrational levels, with ~1 cm−1 root mean square deviation between the calculated rovibrational term values and the available experimental and experimentally derived data. Our computations reproduce the latest laser-induced fluorescence spectrum and provide guidance for the experimental detection of the previously unresolved vibrational levels.

WEAK BOSONS

1989 ◽  
Vol 04 (07) ◽  
pp. 629-632
Author(s):  
SEITARO NAKAMURA
Keyword(s):  
Diatomic Molecule ◽  
Ground State ◽  
Dynamical Model ◽  
Vibrational States ◽  
Vibrational Levels

A dynamical model of weak bosons is presented by taking an analogy of the diatomic molecule. We tentatively assume that the weak bosons now observed are the ground state of the vibrational levels, and expect the possible existence of the exotic weak bosons which correspond to the excited vibrational states, say, 270 GeV, 450 GeV, … The observabilities of these exotic weak bosons are discussed.

The ground-state potential energy curve of the radium dimer from relativistic coupled cluster calculations

2015 ◽  
Vol 143 (8) ◽  
pp. 084307 ◽  
Author(s):  
Tiago Quevedo Teodoro ◽  
Roberto Luiz Andrade Haiduke ◽  
Umakanth Dammalapati ◽  
Steven Knoop ◽  
Lucas Visscher
Keyword(s):  
Potential Energy ◽  
Ground State ◽  
Potential Energy Curve ◽  
Coupled Cluster ◽  
Energy Curve ◽  
Cluster Calculations ◽  
State Potential ◽  
Coupled Cluster Calculations

scholarly journals Straining to React: Delocalization Drives the Stability and Omniphilicity of [1.1.1]propellane

2019 ◽  
Author(s):  
Alistair Sterling ◽  
Russell C. Smith ◽  
Edward Anderson ◽  
Fernanda Duarte
Keyword(s):  
Electronic Structure ◽  
Electron Density ◽  
Ground State ◽  
State Of The Art ◽  
Coupled Cluster ◽  
Complete Active Space ◽  
The Stability ◽  
Highly Strained ◽  
Cluster Methods ◽  
Homo Lumo

The highly strained caged hydrocarbon [1.1.1]propellane has long fascinated chemists with its seemingly paradoxical stability, yet promiscuous reactivity. In this work, we present a unified model of reactivity that accounts for its omniphilic character. Through Complete Active Space (CAS) calculations, state-of-the-art coupled-cluster methods [DLPNO-CCSD(T)] and DFT approaches, we challenge the hypothesis that reactivity of [1.1.1]propellane is driven by strain relief. Instead, a highly delocalized ground-state electronic structure is proposed, where HOMO-LUMO mixing gives a moldable electron density that results in omniphilicity.

Coupled cluster calculations of the ground state potential and interaction induced electric properties of the mixed dimers of helium, neon and argon

2004 ◽  
Vol 102 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Javier López Cacheiro ◽  
Berta Fernández ◽  
Domenico Marchesan ◽  
Sonia Coriani ◽  
Christof Hättig ◽  
...  
Keyword(s):  
Ground State ◽  
Electric Properties ◽  
Coupled Cluster ◽  
Cluster Calculations ◽  
State Potential ◽  
Helium Neon ◽  
Coupled Cluster Calculations

Convergence Properties of Quasiclassical Trajectory Calculations on Dynamics of Autoionization Event in He(23S)-D2 Penning Ionization

1997 ◽  
Vol 62 (2) ◽  
pp. 154-171 ◽  
Author(s):  
Jan Vojtík ◽  
Richard Kotal
Keyword(s):  
Branching Ratios ◽  
Classical Trajectory ◽  
Vibrational States ◽  
Penning Ionization ◽  
Trajectory Calculations ◽  
Quantum Mechanical Treatment ◽  
Total Ionization ◽  
Vibrational Levels ◽  
Degree Of Convergence ◽  
Product Branching

An analysis of the degree of convergence of theoretical pictures of the dynamics of the autoionization event He(23S)-D2(v" = 0) -> [He...D2+(v')] + e is presented for a number of batches of Monte Carlo calculations differing in the number of the trajectories run. The treatment of the dynamics consists in 2D classical trajectory calculations based on static characteristics which include a quantum mechanical treatment of the perturbed D2(v" = 0) and D2+(v') vibrational motion. The vibrational populations are dynamical averages over the local widths of the He(23S)-D2(v" = 0) state with respect to autoionization to D2+(...He) in its v'th vibrational level and the Penning electron energies are related to the local differences between the energies of the corresponding perturbed D2(v" = 0)(...He*) and D2+(v')(...He) vibrational states. Special attention is paid to the connection between the requirements on the degree of convergence of the classical trajectory picture of the event and the purpose of the calculations. Information is obtained regarding a scale of the trajectory calculations required for physically sensible applications of the model to an interpretation of different type of experiments on the system: total ionization cross section measurements, Penning ionization electron spectra, subsequent 3D classical trajectory calculations of branching ratios of the products of the postionization collision process, and interpretation of electron ion coincidence measurements of the product branching ratios for individual vibrational levels of the nascent Penning ion.

Energies and Electric Dipole Moments of the Bound Vibrational States of HN2+ and DN2+

2008 ◽  
Vol 73 (6-7) ◽  
pp. 873-897 ◽  
Author(s):  
Vladimír Špirko ◽  
Ota Bludský ◽  
Wolfgang P. Kraemer
Keyword(s):  
Dipole Moment ◽  
Nearest Neighbor ◽  
Energy Surface ◽  
Dipole Moments ◽  
Three Dimensional ◽  
Vibrational States ◽  
Spacing Distribution ◽  
Triatomic Molecules ◽  
Vibrational Levels ◽  
Different Levels

The adiabatic three-dimensional potential energy surface and the corresponding dipole moment surface describing the ground electronic state of HN2+ (Χ1Σ+) are calculated at different levels of ab initio theory. The calculations cover the entire bound part of the potential up to its lowest dissociation channel including the isomerization barrier. Energies of all bound vibrational and low-lying ro-vibrational levels are determined in a fully variational procedure using the Suttcliffe-Tennyson Hamiltonian for triatomic molecules. They are in close agreement with the available experimental numbers. From the dipole moment function effective dipoles and transition moments are obtained for all the calculated vibrational and ro-vibrational states. Statistical tools such as the density of states or the nearest-neighbor level spacing distribution (NNSD) are applied to describe and analyse general patterns and characteristics of the energy and dipole results calculated for the massively large number of states of the strongly bound HN2+ ion and its deuterated isotopomer.

Sign in / Sign up

Export Citation Format

Share Document