Vertical excitation energies belonging to some
different Rydberg series of hydrogen chloride have beendetermined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculateelectric
dipole transition intensities in HCl and allow ad
ditional assessment of the calculation approach presentlyused to provide an adequate description of the valence and Rydberg states of HCl. The molecular quantumdefect orbital has been applied to the calculation of oscillator strengths. In particular, new insight is given onthe assignment of states as the R
1![](/images/gifchars/Pi.gif)
, the
1![](/images/gifchars/Delta.gif)
(4d
![](/images/gifchars/pi.gif)
and 5p
![](/images/gifchars/pi.gif)
), the
1
+(4d
![](/images/gifchars/pi.gif)
), and the
nd
![](/images/gifchars/delta.gif)
(
1![](/images/gifchars/Pi.gif)
,
1![](/images/gifchars/Phi.gif)
) and 4f states.