Fourier transform emission spectroscopy and ab initio calculations on NbCl

TY - JOUR

T1 - Fourier transform emission spectroscopy and ab initio calculations on NbCl

AU - Ram, R S

AU - Rinskopf, N

AU - Lievin, J

AU - Bernath, P F

PY - 2004/12

Y1 - 2004/12

N2 - The emission spectrum of NbCl has been recorded in the 3000-20000 cm(-1) region using a Fourier transform spectrometer. The bands were observed by microwave excitation of a mixture of NbCl5 vapor and He. Two groups of bands observed in the 6500-7000 cm(-1) and 9800-11000 cm(-1) regions have been assigned to two electronic transitions. Five bands observed in the 6500-7000 cm(-1) region consist of R, P, and Q branches with no combination defect or boolean AND-doubling. They have been assigned as five sub-bands of a Deltaboolean AND = +/-1 transition with boolean AND > 1. Nine bands observed in the 9800-11000 cm(-1) regions consist of R and P branches, and they are also free from boolean AND-doubling. These bands have been classified into four sub-bands of a Deltaboolean AND = 0 transition (with A > 1), which has tentatively been assigned as (5)Delta-(5)Delta. The two transitions have no electronic states in common. Ab initio calculations have been performed on NbCl and the spectroscopic properties of the low-lying electronic states have been calculated. The ground state of NbCl has been predicted to be a (5)Pi state arising from the 3sigma(1) 1delta(2) 2pi(1) configuration, with a low-lying (5)Delta state at 1300cm(-1) from the 3sigma(1) 1delta(1) 2pi(2) configuration. The results of our experimental and theoretical studies will be presented. This work represents the first experimental investigation of the spectra of NbCl and the first ab initio prediction of the spectroscopic properties of the low-lying electronic states. (C) 2004 Elsevier Inc. All rights reserved.

AB - The emission spectrum of NbCl has been recorded in the 3000-20000 cm(-1) region using a Fourier transform spectrometer. The bands were observed by microwave excitation of a mixture of NbCl5 vapor and He. Two groups of bands observed in the 6500-7000 cm(-1) and 9800-11000 cm(-1) regions have been assigned to two electronic transitions. Five bands observed in the 6500-7000 cm(-1) region consist of R, P, and Q branches with no combination defect or boolean AND-doubling. They have been assigned as five sub-bands of a Deltaboolean AND = +/-1 transition with boolean AND > 1. Nine bands observed in the 9800-11000 cm(-1) regions consist of R and P branches, and they are also free from boolean AND-doubling. These bands have been classified into four sub-bands of a Deltaboolean AND = 0 transition (with A > 1), which has tentatively been assigned as (5)Delta-(5)Delta. The two transitions have no electronic states in common. Ab initio calculations have been performed on NbCl and the spectroscopic properties of the low-lying electronic states have been calculated. The ground state of NbCl has been predicted to be a (5)Pi state arising from the 3sigma(1) 1delta(2) 2pi(1) configuration, with a low-lying (5)Delta state at 1300cm(-1) from the 3sigma(1) 1delta(1) 2pi(2) configuration. The results of our experimental and theoretical studies will be presented. This work represents the first experimental investigation of the spectra of NbCl and the first ab initio prediction of the spectroscopic properties of the low-lying electronic states. (C) 2004 Elsevier Inc. All rights reserved.

KW - Fourier transform spectroscopy

KW - emission spectroscopy

KW - Ab initio calculations

KW - CONFIGURATION-INTERACTION CALCULATIONS

KW - POTENTIAL-ENERGY CURVES

KW - ELECTRONIC STATES

KW - PSEUDOPOTENTIALS

KW - ELEMENTS

KW - VCL

KW - 2ND

U2 - 10.1016/j.jms.2004.02.001

DO - 10.1016/j.jms.2004.02.001

M3 - Article

SN - 0022-2852

VL - 228

SP - 544

EP - 553

JO - JOURNAL OF MOLECULAR SPECTROSCOPY

JF - JOURNAL OF MOLECULAR SPECTROSCOPY

IS - 2

ER -