SURESH CHANDRA
Articles written in Pramana – Journal of Physics
Volume 14 Issue 1 January 1980 pp 41-46 Astrophysics
Effect of dielectronic recombination excitation in the solar x-ray lines of calcium-ions
The effect of dielectronic recombination as an excitation process in the intensity of solar x-ray lines of calcium ions is investigated. It is found that x-ray line intensities are enhanced by 15% to 88% with the inclusion of dielectronic recombination as an excitation mechanism.
Volume 25 Issue 5 November 1985 pp 557-563 Atomic And Molecular Physics
Einstein A-coefficients for pure rotational transitions in D2O
Suresh Chandra D A Varshalovich W H Kegel
Einstein A-coefficients for the electric-dipole transitions between the rotational levels up to 785 cm−1 in the ground vibrational state of D2O are calculated. The A-values are used to compute the mean-radiative life-times of the levels.
Volume 47 Issue 1 July 1996 pp 65-77 Research Articles
New method for the evaluation of the RKR potential-integrals for diatomic molecules
Suresh Chandra A K Sharma Z H Khan
We present a new method for the evaluation of the RKR potential-integrals for diatomic molecules. This method is straightforward and fast, and the calculations can be performed to an accuracy better than any other method.
Volume 56 Issue 4 April 2001 pp C585-C587 Comment
Dissociation energy of diatomic molecules – comment on the work of Kaur and Mahajan
When observed spectrum of a diatomic molecule is expressed in terms of the Dunham coefficients $Y_{00}$, $Y_{10}$, $Y_{20}$, $Y_{01}$, and $Y_{11}$ only, dissociation energy of the molecule is given by $Y_{00} + Y^{2}_{10}/(-4Y_{20})$. Kaur and Mahajan [1] have used the Dunham coefficients $Y_{10}$, $Y_{20}$, $Y_{01}$, and $Y_{11}$, for 15 vibrational states of 12 diatomic molecules ($Y_{00}$ is zero for the cases accounted for), but their dissociation energy cannot be reproduced by the expression $Y^{2}_{10}/(-4Y_{20})$. Probable reason for the discrepancy has been discussed.
Volume 62 Issue 4 April 2004 pp 967-971
Einstein
Laboratory formation of four isomers of C5H2 molecule is reported and detection of the ring-chain isomer (isomer 1) of C5H2 in cosmic objects has been suggested. For identification of a molecule in cosmic objects, one of the required input data is Einstein
Volume 62 Issue 5 May 2004 pp C1181-C1185 Comments
Comment on: "Universal relation between spectroscopic constants"
Volume 63 Issue 3 September 2004 pp 627-631
Search for an interstellar Si2C molecule: A theoretical prediction
We suggest that Si2C molecule may be identified in astronomical objects through its transitions 414 → 505, 515 → 606, 212 → 303, 313 → 404, and 111 → 202 at 15.9, 5.1, 33.6, 24.9, and 42.3 GHz in absorption even against the cosmic 2.7 K background, in a region having low temperature. The absorption phenomenon is found rather large in the first two transitions. Dependence of results on the set of molecular parameters is discussed.
Volume 65 Issue 6 December 2005 pp 1133-1137
Relation between spectroscopic constants with limited Dunham coefficients
Statement of Kaur and Mahajan [1] about the definition of Δ used by Chandra [2] is not correct. Even if we take Δ = μωe2re2/2De, the relation between Δ and G(=8ωexe/Be) is obtained as Δ = 4.21452856G, provided the vibrational energy of a diatomic molecule is expressed in terms of limited Dunham coefficients, Y10, Y20, Y01 and Y11. This relation is still different from that of Kaur and Mahajan [3]
Volume 88 Issue 1 January 2017 Article ID 0010 Regular
Rotational quenching of H$_2$CO by molecular hydrogen – Suggestion on the work ofWiesenfeld & Faure
MOHIT KUMAR SHARMA MONIKA SHARMA SURESH CHANDRA
Wiesenfeld and Faure investigated rotational quenching of H$_2$CO by molecular hydrogen where they considered 40 rotational levels of $o$-H$_2$CO and 41 rotational levels of $p$-H$_2$CO. Data on energies of rotationallevels of the molecule are fundamental in the investigation. We have found that the sequence of levels reported by Wiesenfeld and Faure is not as per convention of molecular physics. Their results are also available on the website: http://home.strw.leidenuniv.nl/∼moldata/datafiles/ph2co-h2.dat, where the collisional transitions are shown even between the levels having equal energies. Data for such transitions should not be there.
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