# ABSORPTION INTENSITIES OF THE MULTIPOLE-INDUCED ZERO-PHONON TRANSITIONS IN SOLID HD, HT AND DT

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/20372

Files Size Format View
2002-MF-07.jpg 349.0Kb JPEG image

 Title: ABSORPTION INTENSITIES OF THE MULTIPOLE-INDUCED ZERO-PHONON TRANSITIONS IN SOLID HD, HT AND DT Creators: Mishra, Adya P.; Field, R. W.; Rao, Bhaskara; D'Souza, R.; Balasubramanian, T. K. Issue Date: 2002 Publisher: Ohio State University Abstract: Solid hydrogen as the archetypical molecular quantum crystal, seems to provide endless opportunities and challenges to experimentalists and theorists alike. The absorption process in solid hydrogens ($H_{2}, D_{2}$, HD, etc.) results primarily from induced dipole moments, although the small non-adiabatic allowed dipole contributes to the R-branch transitions for heteronuclear isotopomers. General and special expressions for the integrated absorption coefficients of all types of zero-phonon single and double transitions in solid $H_{2}$ have been derived earlier by different $groups^{a}$. These expressions would also be valid for $D_{2}$ and $T_{2}$ but the definition of ortho- and para- modifications with respect to J (rotational quantum number) will be different. For heteronuclear molecules, the ortho-para distinction does not exist and all the molecules in solid HD, HT and DT are normally in the J=0 state, thus simplifying the infrared spectra and theoretical analysis. However, extra complications arise due to the non-coincidence of the geometric charge center with the center of mass of the molecule. Further, since these molecules are not perfectly centrosymmetric, odd $\Delta J$ transitions are also allowed in addition to even $\Delta J$ transitions, which alone are possible in homonuclear counterparts like $H_{2}$. Although theoretical expressions for the intensities of certain transitions in HD have been derived by Poll and co-$workers^{b}$, so far no attempt is made to give general expressions valid for all transitions of similar types. Currently, we are attempting to derive closed-form expressions for the absorption intensities of single and double transitions in solid HD, HT and DT. The details will be discussed in the present paper. Description: $^{a}$ A. P. Mishra and T. K. Balasubramanian Phys. Rev. B59 (6002), 1999 and references therein. $^{b}$ J. D. Poll, M. Attia and R. H. Tipping Phys. Rev. B39 (11378), 1989 and references therein. Author Institution: Department of Chemistry and G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology; Spectroscopy Division, Bhabha Atomic Research Centre URI: http://hdl.handle.net/1811/20372 Other Identifiers: 2002-MF-07