An ab initio study of PuO2 and of PuN2

被引:23
作者
Archibong, EF [1 ]
Ray, AK [1 ]
机构
[1] Univ Texas, Dept Phys, Arlington, TX 76019 USA
来源
JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM | 2000年 / 530卷 / 1-2期
关键词
ab initio; electronic structure; correlated wavefunctions; ground state; ionization potentials;
D O I
10.1016/S0166-1280(00)00332-8
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Ab initio electronic structure calculations using correlated wavefunctions have been performed to investigate the structures, vibrational frequencies and energetics of PuO2 and PuN2 molecules in their low-lying electronic states. For PuO2, the (5)Sigma(g)(+)- [(1 delta(u))(2)(1 phi(u))(2)] and the (5)Phi(u)-[(1 delta(u))(2)(1 phi(u))(1)(4 sigma(g))(1)] states are found to be nearly degenerate energetically. However, frequency considerations indicate that the (5)Sigma(g)(+) State is the preferred candidate for the ground state. The CCSD(T) computed vertical ionization energy of PuO2 of 9.92 eV compare favorably with the experimentally determined ionization energy of 9.43 eV. For PuN2, the (3)Pi(g)-[(1 delta(u))(1)(1 phi(u))(1)] state is predicted to be the ground state. The omega(3) mode frequency computed for the (3)Pi(g) ground state at the CCSD and CCSD(T) levels, when scaled by 0.93 and 0.92, respectively, agrees perfectly with the nu(3) frequency of 1030 cm(-1) reported from infrared matrix isolation studies. (C) 2000 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:165 / 170
页数:6
相关论文
共 22 条
[1]  
Burke K., 1998, ELECT DENSITY FUNCTI
[2]   AB-INITIO QUANTUM-CHEMICAL CALCULATIONS ON URANYL UO22+ PLUTONYL PUO22+, AND THEIR NITRATES AND SULFATES [J].
CRAW, JS ;
VINCENT, MA ;
HILLIER, IH ;
WALLWORK, AL .
JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (25) :10181-10185
[3]  
DENNING RG, 1992, STRUCT BOND, V79, P215
[4]  
Dolg M, 1998, CHEM-EUR J, V4, P200, DOI 10.1002/(SICI)1521-3765(19980210)4:2<200::AID-CHEM200>3.0.CO
[5]  
2-X
[6]  
Dyall KG, 1999, MOL PHYS, V96, P511, DOI 10.1080/00268979909482988
[7]  
Frisch M.J., 1998, GAUSSIAN98 REVISION
[8]   INFRARED-SPECTRA OF MATRIX-ISOLATED PLUTONIUM NITRIDES [J].
GREEN, DW ;
REEDY, GT .
JOURNAL OF CHEMICAL PHYSICS, 1978, 69 (02) :552-555
[9]   INFRARED-SPECTRA OF MATRIX-ISOLATED PLUTONIUM OXIDES [J].
GREEN, DW ;
REEDY, GT .
JOURNAL OF CHEMICAL PHYSICS, 1978, 69 (02) :544-551
[10]   Theoretical studies of the structures and vibrational frequencies of actinide compounds using relativistic effective core potentials with Hartree-Fock and density functional methods:: UF6, NpF6, and PuF6 [J].
Hay, PJ ;
Martin, RL .
JOURNAL OF CHEMICAL PHYSICS, 1998, 109 (10) :3875-3881