The electronic structure of Ti(BH4)3: Photoelectron spectra and calculation of vertical ionization energies

He I and He II PE spectra of Ti(BH4)3 are reported and assigned by reference to density functional calculations on the molecule and cation. The performance of different functionals in predicting the first vertical ionization energy is assessed. Calculations based on hybrid functionals are found to give ionisation energies closer to the experimental value than those using pure density functionals. The accuracy of the ΔSCF method and time dependent density functional theory in calculating higher vertical ionization energies is also examined.