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Constants of diatomic molecules

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through November, 1976

Symbols used in the table of constants
State electronic state and / or symmetry symbol
Te minimum electronic energy (cm-1)
ωe vibrational constant – first term (cm-1)
ωexe vibrational constant – second term (cm-1)
ωeye vibrational constant – third term (cm-1)
Be rotational constant in equilibrium position (cm-1)
αe rotational constant – first term (cm-1)
γe rotation-vibration interaction constant (cm-1)
De centrifugal distortion constant (cm-1)
βe rotational constant – first term, centrifugal force (cm-1)
re internuclear distance (Å)
Trans. observed transition(s) corresponding to electronic state
ν00 position of 0-0 band (units noted in table)
Diatomic constants for T2
n 3Piu 5ppi (120984.3) 1348.89 22.52  10.021 0.294  0.0022  1.0562 n rarrow a R 24923.03
Cunningham and Dieke, 1950
k 3Piu 4ppi (118403.2) 1355.39 22.026 1 0.133 10.053 0.296  0.0022  1.0545 k rarrow a R 22345.34
Cunningham and Dieke, 1950
f 3Sigmau+ 4psigma (116653) [1278]   9.90 0.30    1.063 f rarrow a R 20561.9
Cunningham and Dieke, 1950
d 3Piu 3ppi (112736.0) 1372.11 22.135 2 0.159 10.150 3 0.3050 3 0.0038 0.00217 4 -0.000065 1.0494 d rarrow a R 16686.44
Dieke and Tomkins, 1949
e 3Sigmau+ 3psigma (107770.8) 1272.28 23.03 5 0.17 9.2056 0.2803 -0.00156 0.1887 -0.000045 1.10197 e rarrow a R 11671.06
Dieke and Tomkins, 1951
a 3Sigmag+ 2ssigma (95965.4) 6 1541.57 24.47 7 0.312 11.4374 0.3258 8    0.98862 (a-x) (95464.4) 9
b 3Sigmau+ 2psigma 10           a rarrow b 
F 1Sigmag+ 2psigma2 (100935.9) 11 [706.0] 12   B8=2.50 13     r8=2.11 F rarrow B R 14
Dieke and Cunningham, 1965
E 1Sigmag+ 2ssigma (100136.7) 1454.18 30.52  10.9306 0.3659  0.2403  1.01128 E rarrow B V 8765.40
Dieke and Cunningham, 1965
C 1Piu 2ppi (100099.7) 6          (C-X) (99536.9) 15
B 1Sigmau+ 2psigma (91696.3) 6 787.28 16 7.013 16  6.716 17 0.2076 17 0.0072 0.173 17 -0.0008 1.2901 (B-X) (90825.0) 18
X 1Sigmag+ 1ssigma2 0 2546.47 19 41.23 19  20.335 19 0.5887 20    (0.74142)  
Cashion, 1966


1missing note
2omegaeze = -0.002.
3The rotational constants refer to 3Pi-; 3Pi+ is perturbed. The Lambda-type doubling is somewhat irregular.
4missing note
5omegaeze = -0.0204.
6From the Te values of H2 and D2 assuming that the electronic isotope shift is proportional to (1 - muH2/muT2).
7omegaeze = -0.016.
8missing note
9From Te assuming Y00 (a 3Sigmag+) = 0 but taking account of Y00 in the ground state X 1Sigmag+ (see 19).
10Repulsive state, lower state of T2 continuum.
11From the observed v80 and the energy of v=8 above the outer minimum of the E,F double-minimum state as calculated by Kolos and Wolniewicz, 1969.
12Calculated DeltaG(1/2) value for the outer minimum Kolos and Wolniewicz, 1969.
13Vibrational numbering of Kolos and Wolniewicz, 1969. The D8 value is large and negative. For higher vibrational levels (above the potential maximum) Bv is larger, e.g. Dieke and Cunningham, 1965 give B13 = 3.892 Dieke and Cunningham, 1965, and D13 = 0.00109 has the normal sign, in agreement with the fact that for these levels the vibrational motion covers both minima of the E,F state. v=0...7 levels not yet observed.
14According to Kolos and Wolniewicz, 1969 the lowest level of the outer minimum is expected at 9204.5 cm-1 above B 1Sigmau+(v=0). The v=8 level lies just below the potential maximum.
15From Te and the zero-point energy calculated by Kolos and Wolniewicz, 1968.
16From the R(0) lines in the E,F-B system Dieke and Cunningham, 1965: omegaeye = +0.0912 Dieke and Cunningham, 1965. The zero-point energy (Y00 = 2.6 included) is 394.46 cm-1.
17From combination differences formed from the data on E,F-B Dieke and Cunningham, 1965; betae = -0.0008.
18From the calculated Te and the zero-point energies as given in 16 and 19.
19Calculated by Cashion, 1966 from the potential function of Kolos and Wolniewicz, 1965 and based on v = 0...3 only: experimental values are not available. The zero-point energy (Y00 = 2.8 included) is 1265.74 cm-1.
20alphav= +0.0053(v+1/2)2 - 0.00018(v+1/2)3; see 19.
21D00= 37028.4 cm-1 Kolos and Wolniewicz, 1968, 2, calculated from ab initio potential function Kolos and Wolniewicz, 1968, 2; non- adiabatic corrections which are certainly less than +0.2 cm-1 and Lamb shift corrections (~ 0.2 cm-1) are not included. No observed value is available yet.
22From the theoretical values of D00(T2) and D00(T2+), and I.P.(T).


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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Cunningham and Dieke, 1950
Cunningham; Dieke, Johns Hopkins University, Department of Physics, Rpt. NYO-692, 1950, 1. [all data]

Dieke and Tomkins, 1949
Dieke, G.H.; Tomkins, F.S., The molecular spectrum of hydrogen. The Fulcher bands of TH and T2, Phys. Rev., 1949, 76, 283. [all data]

Dieke and Tomkins, 1951
Dieke, G.H.; Tomkins, F.S., The 3p3«SIGMA»-->2s3«SIGMA»-bands of TH and T2, Phys. Rev., 1951, 82, 796. [all data]

Dieke and Cunningham, 1965
Dieke, G.H.; Cunningham, S.P., Bands of D2 and T2 originating from the lowest excited 1«SIGMA»g states (1s«sigma»)(2s«sigma»)1«SIGMA»g and (2p«sigma»)21«SIGMA»g, J. Mol. Spectrosc., 1965, 18, 288. [all data]

Cashion, 1966
Cashion, J.K., Properties of the 1«SIGMA»g+ state of H2 calculated from an accurate adiabatic potential, J. Chem. Phys., 1966, 45, 1037. [all data]

Kolos and Wolniewicz, 1969
Kolos, W.; Wolniewicz, L., Theoretical investigation of the lowest double-minimum state E, F1«SIGMA»g+ of the hydrogen molecule, J. Chem. Phys., 1969, 50, 3228. [all data]

Kolos and Wolniewicz, 1968
Kolos, W.; Wolniewicz, L., Vibrational and rotational energies of the B1«SIGMA»u+, C1«PI»u, C1«PI»u, and a3«SIGMA»g+ states of the hydrogen molecule, J. Chem. Phys., 1968, 48, 3672. [all data]

Kolos and Wolniewicz, 1965
Kolos, W.; Wolniewicz, L., Potential-energy curves for the X1«SIGMA»g+, b3«SIGMA»u+, and C1«PI»u states of the hydrogen molecule, J. Chem. Phys., 1965, 43, 2429. [all data]

Kolos and Wolniewicz, 1968, 2
Kolos, W.; Wolniewicz, L., Improved theoretical ground-state energy of the hydrogen molecule, J. Chem. Phys., 1968, 49, 404. [all data]


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