Silylidyne cation

Formula: HSi⁺
Molecular weight: 29.0929
CAS Registry Number: 31241-66-4
Information on this page:
Other data available:
- Gas phase thermochemistry data
Options:
- Switch to calorie-based units

Constants of diatomic molecules

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

Data collected through August, 1977

Symbols used in the table of constants
Symbol	Meaning
State	electronic state and / or symmetry symbol
T_e	minimum electronic energy (cm^-1)
ω_e	vibrational constant – first term (cm^-1)
ω_ex_e	vibrational constant – second term (cm^-1)
ω_ey_e	vibrational constant – third term (cm^-1)
B_e	rotational constant in equilibrium position (cm^-1)
α_e	rotational constant – first term (cm^-1)
γ_e	rotation-vibration interaction constant (cm^-1)
D_e	centrifugal distortion constant (cm^-1)
β_e	rotational constant – first term, centrifugal force (cm^-1)
r_e	internuclear distance (Å)
Trans.	observed transition(s) corresponding to electronic state
ν₀₀	position of 0-0 band (units noted in table)

Diatomic constants for ²⁸SiH⁺
State	T_e	ω_e	ω_ex_e	B_e	α_e	γ_e	D_e	β_e	r_e	Trans.	ν₀₀
A ¹Π	25846.₁	[390.17] Z	(72.0) 1	4.9125 2	0.7667		[19.92E-4] 3		1.8782	A → X 4 5 R	25025.20 Z
A ¹Π	↳Douglas and Lutz, 1970; missing citation
X ¹Σ⁺	0	2157.17 Z	34.24	7.6603	0.2096	.0045₅	3.83E-4	-5E-6	1.5041

Notes

Estimated from Pekeris' relation Douglas and Lutz, 1970.

From average B_v values for the two Λ-doubling components; B(P,R) - B(Q) = +0.0062, +0.0156 (v=0,1).

D₁= 17.89E-4. In both v=0 and 1, rotational levels having J ≥ 9 cannot be represented by short power series in J(J+1).

Also observed in the solar spectrum Grevesse and Sauval, 1970. On the basis of this observation Grevesse and Sauval, 1971 obtain f₀₀ = 0.0005 Grevesse and Sauval, 1971; see, however, Liszt and Smith, 1972.

Potential functions, Franck-Condon factors Rao and Lakshman, 1971, Liszt and Smith, 1972.

From a short extrapolation of the vibrational levels in A ¹Π Douglas and Lutz, 1970.

Table IV as well as eqn. [3] and eqn. [5] of Douglas and Lutz, 1970 contain several errors which were later corrected in an unpublished erratum.

References

Go To: Top, Constants of diatomic molecules, Notes

Douglas and Lutz, 1970
Douglas, A.E.; Lutz, B.L., Spectroscopic identification of the SiH⁺ molecule: the A 1π-X1⁺ system, Can. J. Phys., 1970, 48, 247. [all data]

Grevesse and Sauval, 1970
Grevesse, N.; Sauval, A.J., Identification of SiH⁺ in the solar photospheric spectrum, Astron. Astrophys., 1970, 9, 232-238. [all data]

Grevesse and Sauval, 1971
Grevesse, N.; Sauval, A.J., Oscillator strengths for SiH and SiH⁺ deduced from the solar spectrum, J. Quant. Spectrosc. Radiat. Transfer, 1971, 11, 65. [all data]

Liszt and Smith, 1972
Liszt, H.S.; Smith, W.H., RKR Franck-Condon factors for blue and ultraviolet transitions of some molecules of astrophysical interest and some comments on the interstellar abundance of CH, CH⁺, and SiH, J. Quant. Spectrosc. Radiat. Transfer, 1972, 12, 947. [all data]

Rao and Lakshman, 1971
Rao, T.V.R.; Lakshman, S.V.J., The true potential energy curves and Franck-Condon factors of SiH and SiH⁺ molecules, Physica, 1971, 56, 322. [all data]

Notes

Go To: Top, Constants of diatomic molecules, References

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.