A gas-phase sample consisting of lithium iodide, $\mathrm{LiI}$, molecules and their dimer ${\left(\mathrm{LiI}\right)}_2$ are Coulomb exploded by an intense 25-fs laser pulse. In the case of $\mathrm{LiI}$, we focus on the double ionization that creates a pair of ${\mathrm{Li}}^{+}$ and ${\mathrm{I}}^{+}$ recoil ions. From the kinetic energy distribution of the ${\mathrm{Li}}^{+}$ ions, extracted using coincidence filtering, we determine the distribution of internuclear distances $P\left(R\right)$ via the ground-state potential curve of ${\mathrm{LiI}}^{2+}$ obtained from an ab initio calculation that accounts for non-Coulombic effects. We find that the center of $P\left(R\right)$ is close to the expected internuclear separation based on the three vibrational states of $\mathrm{LiI}$ populated, whereas the width of $P\left(R\right)$ exceeds the theoretical value by $\sim 52$%. We discuss whether fragmentation via excited ${\mathrm{LiI}}^{2+}$ potential curves affects the determination of $P\left(R\right)$. In the case of the dimer, ${\left(\mathrm{LiI}\right)}_2$, we observe kinetic energies and relative emission directions of ${\mathrm{Li}}^{+}, {\mathrm{I}}^{+}$, and ${\mathrm{I}}^{2+}$ recoil ions consistent with Coulomb explosion of the parallelogram-shaped dimer after removing up to six electrons by the laser pulse.

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• Chemical binding
• Interatomic & molecular potentials
• Light-matter interaction
• Multiphoton or tunneling ionization & excitation
• Potential energy surfaces
• Single- and few-photon ionization & excitation
• Strong electromagnetic field effects