中国物理B ›› 2006, Vol. 15 ›› Issue (7): 1517-1521.doi: 10.1088/1009-1963/15/7/023

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Spin polarization effect for Fe2 molecule

朱正和1, 阎世英2   

  1. (1)Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China; (2)Physics Department, College of Physical Science, Qingdao University, Qingdao 266071, China;Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
  • 收稿日期:2006-01-18 修回日期:2006-02-14 出版日期:2006-07-20 发布日期:2006-07-20

Spin polarization effect for Fe2 molecule

Yan Shi-Ying (阎世英)ab, Zhu Zheng-He (朱正和)b    

  1. a Physics Department, College of Physical Science, Qingdao University, Qingdao 266071, China; b Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
  • Received:2006-01-18 Revised:2006-02-14 Online:2006-07-20 Published:2006-07-20

摘要: This paper uses the density functional theory (DFT)(B3p86) of Gaussian03 to optimize the structure of Fe2 molecule. The result shows that the ground state for Fe2 molecule is a 9-multiple state, which shows spin polarization effect of Fe2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, that the ground state for Fe2 molecule is a 9-multiple state is indicative of the spin polarization effect of Fe2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of the Fe2 molecule is minimized. It can be concluded that the effect of parallel spin of the Fe2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell--Sorbie potential functions with the parameters for the ground state and other states of Fe2 molecule are derived. Dissociation energy De for the ground state of Fe2 molecule is 2.8586ev, equilibrium bond length Re is 0.2124nm, vibration frequency \omega e is 336.38,cm-1. Its force constants f2, f3,and f4 are 1.8615aJ\cdotnm-2, --8.6704aJ\cdotnm-3, 29.1676aJ\cdotnm-4 respectively. The other spectroscopic data for the ground state of Fe2 molecule \omegae \chie, Be, \alphae are 1.5461,cm-1, 0.1339,cm-1,7.3428×10-4,cm-1 respectively.

关键词: Fe2, spin polarization, density functional theory, potential function

Abstract: This paper uses the density functional theory (DFT)(B3p86) of Gaussian03 to optimize the structure of Fe2 molecule. The result shows that the ground state for Fe2 molecule is a 9-multiple state, which shows spin polarization effect of Fe2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, that the ground state for Fe2 molecule is a 9-multiple state is indicative of the spin polarization effect of Fe2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of the Fe2 molecule is minimized. It can be concluded that the effect of parallel spin of the Fe2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell--Sorbie potential functions with the parameters for the ground state and other states of Fe2 molecule are derived. Dissociation energy De for the ground state of Fe2 molecule is 2.8586ev, equilibrium bond length Re is 0.2124nm, vibration frequency $\omega_{\rm e}$ is 336.38 cm-1. Its force constants f2, f3, and f4 are 1.8615aJ$\cdot$nm-2, -8.6704aJ$\cdot$nm-3, 29.1676aJ$\cdot$nm-4 respectively. The other spectroscopic data for the ground state of Fe2 molecule $\omega_{\rm e}\chi_{\rm e}$, Be, $\alpha_{\rm e}$ are 1.5461 cm-1, 0.1339 cm-1, 7.3428×10-4 cm-1 respectively.

Key words: Fe2, spin polarization, density functional theory, potential function

中图分类号: 

  • 31.15.E-
31.50.-x (Potential energy surfaces) 33.15.Dj (Interatomic distances and angles) 33.15.Fm (Bond strengths, dissociation energies) 33.15.Mt (Rotation, vibration, and vibration-rotation constants)