Hyperfine Structure Constants on the Relativistic Coupled Cluster Level with Associated Uncertainties
Pi A B Haase1, Ephraim Eliav2, Miroslav Iliaš3
1Van Swinderen Institute, University of Groningen, 9747 Groningen, The Netherlands.
The Journal of Physical Chemistry. A
|March 24, 2020
Summary
Accurate hyperfine structure (HFS) constant predictions are crucial. Relativistic coupled cluster methods show excellent performance, with calculated HFS constants deviating less than 1% from experimental values.
Area of Science:
- Quantum Chemistry
- Atomic Physics
- Spectroscopy
Background:
- Accurate hyperfine structure (HFS) constants are vital for nuclear property determination and theoretical method benchmarking.
- Previous theoretical methods have limitations in predicting HFS constants with high accuracy.
Purpose of the Study:
- To investigate the performance of relativistic coupled cluster (RCC) methods for calculating HFS constants.
- To provide a reliable theoretical uncertainty estimate for HFS constant calculations.
Main Methods:
- Employed the finite-field relativistic coupled cluster (RCC) approach.
- Calculated HFS constants for 133Cs and 137BaF systems.
- Developed a theoretical uncertainty estimate considering basis set, electron correlation, and relativistic effects.
Main Results:
- The relativistic coupled cluster method demonstrates high accuracy in predicting HFS constants.
- Calculated HFS constants showed a deviation of less than 1% from experimental values.
- Higher-order electron correlation contributions were the largest source of uncertainty.
Conclusions:
- Relativistic coupled cluster methods are highly effective for accurate HFS constant calculations.
- A conservative uncertainty estimate of approximately 5.5% was established.
- The study validates RCC methods for fundamental physics and chemistry applications.
Related Concept Videos
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
1.4K
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are...
1.4K
01:22Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
1.4K
Vicinal or three-bond coupling is commonly observed between protons attached to adjacent carbons. Here, nuclear spin information is primarily transferred via electron spin interactions between adjacent C‑H bond orbitals. This generally favors the antiparallel arrangement of spins, so 3J values are usually positive.
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
1.4K
01:17Spin–Spin Coupling: One-Bond Coupling
1.3K
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
1.3K
04:08The Uncertainty Principle
31.0K
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...
31.0K
01:08Spin–Spin Coupling Constant: Overview
1.4K
In bromoethane, the three methyl protons are coupled to the two methylene protons that are three bonds away. In accordance with the n+1 rule, the signal from the methyl protons is split into three peaks with 1:2:1 relative intensities. The methylene protons appear as a quartet, with the relative intensities of 1:3:3:1.
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
1.4K
02:58Crystal Field Theory - Octahedral Complexes
30.1K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
30.1K