The coherent superposition of cation states can result in charge migration on the natural time scale of electron dynamics in molecules. Strong field ionization can produce suitable coherent superpositions of the ground and excited states of a cation, but the resulting charge migration may be challenging to observe experimentally. Modeling the decoherence of charge migration requires information about the potential energy surfaces of the relevant states of the cation. Some of this information can be gleaned from photoelectron spectra, but these spectra are often dense and difficult to analyze. Computational methods can provide structures and vibrational frequencies of the ground and excited states of cations to help analyze photoelectron spectra and to simulate electron dynamics in coherent superpositions of cation states. In the present computational study, we examine the ground and excited states of a series of haloacetylene cations, HCCX + (X = F, Cl, Br, I), in preparation for future studies on the formation of coherent superpositions and the simulation of charge migration in these systems.