Knowledge Bank

More than 40 vibration-rotation transitions in the $v3-2,a\leftarrow v2=1s$ hot bands of $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}NH4$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}NH3$ have been recorded by using the sidebands on $CO2$ laser lines generated in a CdTe crystal by application of an X-band or P-band microwave electric field. The spectra were observed at Doppler-limited resolution and individual lineshapes were fit to a Voigt profile. The experimental accuracy of the center frequencies is better than $0.00003cm-1$ in favorable cases. Hot band transitions have also been recorded for $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}NH3$ at $0.005cm-1$ resolution by the Kitt Peak McMath Solar Telescope 1 m interferometer. Similar transitions in $\mathrm{<mrow\; data-mjx-texclass="ORD">15</mrow>}NH3$ have been obtained at Michigan State University at $0.01cm-1$ resolution by means of a BOMEM Fourier transform spectrometer. Nearly all of the measured frequencies from the Kitt Peak spectra agree with the sideband laser values to better then $0.00007cm-1$. Molecular constants for the $v2=2$, a states for both isotopic species will be reported.