Towards core-excitation spectra in attosecond spectroscopy: A coupled-cluster study of ClF

The increasing availability of short timescale spectroscopy techniques allows for more accurate probing of nuclear and electronic dynamics. This work studies the underlying potential energy curves for the core-ionized and core-excited states of ClF. The variational collapse that can occur using conventional variational methods make electronic states involving core-holes particularly challenging to describe. Coupled-cluster methods can avoid such problems. This work applies extensions of ground and excited state coupled-cluster methods to compute potential curves for core-hole states of ClF. The ability to obtain accurate potential curves for such elusive states, and generate core-absorption spectra, opens the door for exciting developments. (C) 2017 Elsevier B.V. All rights reserved.