• Title/Summary/Keyword: Lithium dimer

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Study of the Valence and Rydberg States of a Lithium Dimer by the Multi-reference Configuration-interaction Method

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1422-1432
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    • 2014
  • Convergent all-electron multi-reference configuration-interaction (MRCI) calculations are performed for a lithium dimer with Kaufmann's Rydberg basis functions. A comparison of the results of these calculations with those of the effective core potential/core polarization potential (ECP/CPP) method and experimental data reveals the deficiency of the all-electron ab initio method. The deficiency is related to the mere 51.9% attainment of electron correlation for the ground state. The percent attainment of electron correlation for the first excited state is slightly better than that for the ground state, preventing us from obtaining better agreements with experimental data by means of increasing the size of basis sets. The Kaufmann basis functions are then used with the ECP/CPP method to obtain the accurate convergent potential energy curves for the $^1\prod_u$ states correlated to Li(2p) + Li(2p) and Li(2s) + Li(n = 2, 3, 4). Quantum defect curves (QDCs) calculated for both the $X^2\sum_g$ and 1 $^2\prod_u$ states of the $Li{_2}^+$ ion and the Lu-Fano plot reveal a strong series-series interaction between the two $2snp{\pi}$ and $2pnp{\pi}$ Rydberg series. The QDCs are then used to resolve assignment problems in the literature. The reassignments, performed by Jedrzejewski-Szemek et al., of the dissociation product of the D $^1\prod$ state from (2s+3d) to (2s+3p) and that of the 6 $^1\prod_u$ from (2s+4d) to (2s+4p) are found to be incorrect. It may be more natural to assign their $2snp{\pi}$ Rydberg series as a $2snd{\pi}$ series. The state, assigned as 5p $^1\prod_u$ by Ross et al. and 4d $^1\prod$ by Jedrzejewski-Szemek et al., is assigned as the 7 $^1\prod_u$ state, correlated to the Li(2s) + Li(4f) limit.

Molecular Spinless Energies of the Modified Rosen-Morse Potential Energy Model

  • Jia, Chun-Sheng;Peng, Xiao-Long;He, Su
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2699-2703
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    • 2014
  • We solve the Klein-Gordon equation with the modified Rosen-Morse potential energy model. The bound state energy equation has been obtained by using the supersymmetric shape invariance approach. The relativistic vibrational transition frequencies for the $6^1{\Pi}_u$ state of the $^7Li_2$ molecule have been computed by using the modified Rosen-Morse potential model. The calculated relativistic vibrational transition frequencies are in good agreement with the experimental RKR values.

Physical Properties of the Langmuir-Blodgett Films Layered with Octadecylviologen-TCNQ (Octadecylviologen-TCNQ LB 막의 물리적 특성)

  • 신동명;박제상;강도열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.77-80
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    • 1995
  • Enhancing the electrical conductivity of the ultrathin organic films using Langmuir-Blodget technique is important step for the developement of molecular electronic device. The Octadecylviologen-TCNQ was synthesized with Octadecylviologen-Bromide an Lithium TCNQ Sine Octadecylviologen-TCNQ has two TCNQ snion radicals, the conductivity of LB film is expected to increase. The $\pi$-A isotherm showed that the limiting area was 150${\AA}$$\^$2/ molecule and the silid-like transition surface pressure was 25 mN/m. The electronic transition of the TNCNQ anion radical was observed at 400 nm. Intermolecular charge transfer absorption was observed at 600nm and 850~1050 nm which ay resulted from the TCNQ anion radical dimer formation. The electrical conductivity of the viologen -TCNQ LB film was 10$\^$-6/cm This values was 100 times higher than that of the quinolinium-TCNQ and pyridinium-TCNQ LB films.

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Synthesis of $\pi$-Allyl-type Cobalt, Palladium, Platinum Complexes Having a $C_2$-Chiral Ligand ($C_2$ 손대칭 리간드를 배위하는 $\pi$-Allyl-Cobalt, Palladium, Platinum 착물의 생성)

  • Uhm, Jae Kook;Lee, Jong O;An, Hee Won
    • Journal of the Korean Chemical Society
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    • v.42 no.2
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    • pp.177-183
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    • 1998
  • By the reactions of a $C_{2}$-chiral ligand, (+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene(6) with $[\pi-allyl chloroplatinum(II)]_4$, and $CpCo(CO)_2$ respectively, three new complexes, ($\pi$-allyl)platinum(II)(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene perchlorate(1), ($\pi$-allyl)platinum(II)(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene chloride(2), ($\eta^5$-cyclopentadienyl)cobalt(I)-(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene(3) were prepared. $\eta^3$-Cyclohexenyl)palladium(II)1,2-bis(diphenylphosphino)ethane perchlorate(4) was obtained by the reaction of ($\eta^3$-cyclohexenyl)palladium(II) chloride dimer with a symmetric ligand, 1,2-bis(diphenylphosphino)ethane and lithium perchlorate. These complexes were identified by NMR-, IR-, and Mass-Spectrophotometers and elemental analyzer.

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