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Anharmonic force fields of perchloric acid, HClO$_4$, and perchloric anhydride, Cl$_2$O$_7$. An extreme case of inner polarization

A. Daniel Boese·Jan M. L. Martin
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Abstract

DFT (density functional theory) anharmonic force fields with basis sets near the Kohn-Sham limit have been obtained for perchloric acid, HClO$_4$, and perchloric anhydride, Cl$_2$O$_7$. Calculated fundamental frequencies are in very good agreement with available experimental data. Some reassignments in the vibrational spectra of Cl$_2$O$_7$ are proposed based on our calculations. HClO$_4$ and Cl$_2$O$_7$ are particularly severe examples of the `inner polarization' phenomenon. The polarization consistent basis sets pc-1 and pc-2 (as well as their augmented counterparts) should be supplemented with two (preferably three) and one (preferably two) high-exponent $d$ functions, respectively, on second-row atoms. Complete anharmonic force fields are available as electronic supporting information.

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A. Daniel Boese, Jan M. L. Martin. 2005-08-11. Anharmonic force fields of perchloric acid, HClO$_4$, and perchloric anhydride, Cl$_2$O$_7$. An extreme case of inner polarization. https://doi.org/10.1016/j.molstruc.2005.07.009

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