Vibrational transition moments of CH$_4$ from first principles
Abstract
A new nine-dimensional (9D), \textit{ab initio} electric dipole moment surface (DMS) of methane in its ground electronic state is presented. The DMS is computed using an explicitly correlated coupled cluster CCSD(T)-F12 method in conjunction with an F12-optimized correlation consistent basis set of the TZ-family. A symmetrized molecular bond representation is used to parameterise the 9D DMS in terms of sixth-order polynomials. Vibrational transition moments as well as band intensities for a large number of IR-active vibrational bands of CH are computed by vibrationally averaging the \textit{ab initio} dipole moment components. The vibrational wavefunctions required for these averages are computed variationally using the program TROVE and a new `spectroscopic' CH potential energy surface. The new DMS will be used to produce a hot line list for CH.
Keywords
Cite
@article{arxiv.1302.1720,
title = {Vibrational transition moments of CH$_4$ from first principles},
author = {Sergei N. Yurchenko and Jonathan Tennyson and Robert J. Barber and Walter Thiel},
journal= {arXiv preprint arXiv:1302.1720},
year = {2014}
}
Comments
J. Molec. Spectrosc. (submitted)