• 대한화학회지
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• 제23권2호
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• pp.65-74
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• 1979

팔면체$ [Ti(Ⅲ)A_3B_3]$, $ [V(Ⅲ)A_3B_3]$, $ [Fe(Ⅲ)A_3B_3]$ 및 $ [Ni(Ⅱ)A_3B_3]$ 형태 착물의 바닥상태에 대한 리간드 궤도함수의 spin-orbit coupling의 영향을 고찰하여 보았다. 리간드 궤도함수의 spin-orbit coupling이 바닥상태의 파동함수에는 영향을 주지 않았으나 에너지 준위의 분열에는 영향을 주었으며, 그 크기는 Ti(Ⅲ) > V(Ⅲ) > Fe(Ⅲ)의 순서로 감소하였다

• 천문학회보
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• 제44권1호
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• pp.35.1-35.1
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• 2019

We present a statistical analysis on the spin-orbit alignment of dark matter halo pairs in cosmological simulations. The alignment is defined as the angular concurrence between the halo spin vector (${\vec{S}}$) and the orbital angular momentum vector (${\vec{L}}$) of the major companion. We identify interacting halo pairs with the mass ratios from 1:1 to 1:3, with the halo masses of 10.8 < $Log(M_{halo}/M_{sun}$) < 13.0, and with the separations smaller than a sum of their virial radii ($R_{12}<R_{1,vir}+R_{2,vir}$). Based on the total energy ($E_{12}$), the pairs are classified into flybys ($E_{12}$ > 0) and mergers ($E_{12}{\leq}0$). By measuring the angle (${\theta}_{SL}$) between ${\vec{S}}$ and ${\vec{L}}$, we confirm a strong spin-orbit alignment signal such that the halo spin is preferentially aligned with the orbital angular momentum of the major companion. We find that the signal of the spin-orbit alignment for the flyby is weaker than that for the merger. We also find an unexpected excess signal of the spin-orbit alignment at $cos{\theta}_{SL}{\sim}0.25$. Both the strength of the spin-orbit alignment and the degree of the excess depend only on the environment. We conclude that the halo spin is determined by the accretion in a preferred direction set by the ambient environment.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 추계학술발표대회 및
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• pp.57.1-57.1
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• 2007

• 한국진공학회지
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• 제4권3호
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• pp.334-341
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• 1995

IB-AI-VIB2 및 IB-AI-VIB2 :Co2+ 결정을 고순도 원소를 출발 물질로 하고 iodine을 수송 매체로 사용하여 chemical transport reaction method로 성장시켰다. 성장된 결정의 결정구조는 chalcopyrite 구조였으며, energy gap은 direct band gap으로 3.514~1.814 eV 정도로 주어졌으며, cobalt를 불순물로 첨가할 때 energy gap은 감소하였다. IB-AI-VIB2 :Co2+ 결정에서 첨가된 cobalt가 모체결정의 Td symmetry site에 Co2+ ion으로 위치하여, Co2+ ion의 energy 준위 사이의 전자전이에 기인하는 불순물 광흡수 peaks가 나타났다. 이 불순물 광흡수 peaks에 결정장 이론을 적용하여 구산 1st-order spin-orbit coupling parameter(λ)는 -183~ -189cm-1정도였고, 2nd-order spin-orbit coupling parameter(P)는 225~239 cm-1정도였으며, crystal field parameter(Dq)는 328~395cm-1, Racah parameter(B)는 531~552cm-1정도였다.

• Journal of Magnetics
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• 제16권1호
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• pp.1-5
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• 2011

The magnetism and electronic structure of bcc $Al_1Fe_{26}$ was investigated by means of first-principles calculations with and without spin-orbit coupling (SOC). From the calculated total energy, the SOC corrected system is shown to be approximately 5 meV per atom lower than the SOC uncorrected system. The induced spin magnetic moment at the Al site was -0.125 ${\mu}_B$ without SOC and -0.124 ${\mu}_B$ with SOC. The orbital magnetic moments were calculated to be 0.002 ${\mu}_B$ in [$\overline{1}$00] direction for Al. The electronic structures showed the nearest neighbor antiferromagnetic interaction between Fe and Al to be essential for determining the magnetism of the $Al_1Fe_{26}$ system.

• 한국자기학회지
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• 제21권1호
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• pp.1-4
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• 2011

정육면체 전이금속 산화물 FeO, MnO의 자기적 상호작용을 제1원리의 범밀도함수법을 이용하여 계산하였다. 그 결과, 모두 초교환작용으로 인해 반강자성적 상호작용이 가장 낮은 에너지를 가지고 있었다. 자기이방성은 반강자성 스핀 배열의 FeO 클러스터에서만 발견되었다. 그 원인은 <111> 방향으로 각운동량을 가지는 3d down-spin 전자의 스핀-궤도 결합에 기인하였다.

• Bulletin of the Korean Chemical Society
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• 제16권6호
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• pp.547-552
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• 1995

As an extension to the Kramers' restricted Hartree-Fock (KRHF) method [J. Comp. Chem., 13, 595 (1992)], we have implemented the Kramers' restricted configuration interaction (KRCI) program in order to calculate excited states as well as the ground state of polyatomic molecules containing heavy atoms. This KRCI is based on determinants composed of the two-component molecular spinors which are generated from KRHF calculations. The Hamiltonian employed in the KRHF and KRCI methods contains most of all the important relativistic effects including spin-orbit terms through the use of relativistic effective core potentials (REP). The present program which is limited to a small configuration space has been tested for a few atoms and molecules. Excitation energies of the group 14 and 16 elements calculated using the present KRCI program are in good accordance with the spectroscopic data. Calculated excitation energies for many Rydberg states of K and Cs indicate that spin-orbit terms in the REP, which are derived for the ground state, are also reliable for the description of highly excited states. The electronic states of the polyatomic molecule CH3I are probed from the molecular region to the dissociation limit. Test calculations demonstrate that the present KRCI is a useful method for the description of potential energy surface of polyatomic molecules containing heavy atoms.

• 대한화학회지
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• 제34권1호
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• pp.37-43
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• 1990

$D_{2d}$ 점군에 속하는 강결정장의 tetragonally 일그러진 사면체 3$d^9$전자계 착물의 바닥상태에 대한 리간드 궤도함수의 spin-orbit coupling과 중심 금속의 3d와 4p궤도함수의 intermixing이 미치는 영향에 대하여 중첩 섭동론을 사용하여 연구하였다. 단결정 $Cs_2CuCl_4$의 tetragonally 일그러진 $CuCl_4^{2-}$에 대한 d-d전이의 실험값을 사용한 LCAO-MO분석은 구리이온과 리간드 사이의 공유결합성은 Cu 4p orbital의 기여가 증가하므로서 급격히 감소하고 리간드 Cl 3p궤도함수의 spin-orbit coupling 상호작용에 의한 바닥상태의 에너지 준위 분리에 대한 효과는 $\Gamma_7(E)\;\to\;\Gamma_6(E)\; >\;\Gamma_7(B_2)\;\to\;\Gamma_6(E)\; >\;\Gamma_7(B_2)\;\to\;\Gamma_7(E)$의 순서로 감소하였다.

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.122-126
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• 1987

Oribtal energies for AuH and AgH are calculated by an all-electron relativistic self-consistent-field method using Slater type basis functions. Major relativistic effects for AgH are spin-orbit splittings and those for AuH are large shifts in orbital energies in addition to spin-orbit splittings. Relativistic effects on orbital energies in AgH and AuH imply that changes in correlation energies for relativistic calculations of AuH will be significantly larger than those of AgH, providing partial explanation for the large discrepencies in equilibrium bond length and the dissociation energy between experiments and theoretical estimates for AuH. Large relativistic effects on orbital energies indicate that relativistic contributions should be included for the correct interpretation of ionization potentials for these molecules. Relativistic effects are also evident in dipole moments for these molecules.

• 천문학회보
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• 제46권1호
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• pp.28.1-28.1
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• 2021

We present a statistical analysis of dark matter halos with interacting neighbors using a set of cosmological simulations. We classify the neighbors into two groups based on the total energy (E₁₂) of the target-neighbor system; flybying neighbors (E₁₂ ≥ 0) and merging ones (E₁₂ < 0). First, we find a different trend between the flyby and merger fractions in terms of the halo mass and large-scale density. The flyby fraction highly depends on the halo mass and environment, while the merger fraction show little dependence. Second, we measure the spin-orbit alignment, which is the angular alignment between the spin of a target halo (${\vec{S}}$ ) and the orbital angular momentum of its neighbor (${\vec{L}}$). In the spin-orbit angle distribution, the flybying neighbors show a weaker prograde alignment with their target halos than the merging neighbors do. With respect to the nearest filament, the flybying neighbor has a behavior different from that of the merging neighbor. Finally, we discuss the physical origin of two interaction types.