Carbon geometry of ${\mathrm{C}}_3$${\mathrm{H}}_3^{+}$ and ${\mathrm{C}}_3$${\mathrm{H}}_4^{+}$ molecular ions probed by laser-induced Coulomb explosion

The structure of ${\mathrm{C}}_3$ ${\mathrm{H}}_3^{+}$ and ${\mathrm{C}}_3$ ${\mathrm{H}}_4^{+}$ ions produced by nonresonant multiphoton ionization is determined using laser-induced Coulomb explosion and associated multicharged atomic ion momenta correlations. Both cations exhibit the same ${\mathrm{C}}_3$ average elongated linear carbon geometry. Stretched and bent nuclear configurations around the average structure are included in the calculations in order to reproduce the observed ion-ion correlation peak shapes.