SINGLET-TRIPLET GAP IN HCI HALOCARBENE

The singlet-triplet energy separation, geometrical structure, harmonic vibrational frequencies, adiabatic ionization potential and electron affinity, dissociation energies and dipole moment for HCI have been de termined by using the linear combination of Gaussian-type orbital-loca l spin density method (LCGTO-LSD) and employing both the local and non local exchange and correlation potentials. Computations show that HCI has a singlet ground state (1A1) in agreement with a previous theoreti cal result but in disagreement with recent experimental data. The sing let-triplet energy splitting is found to be 3.7 kcal/mol at the nonloc al level of computation. The calculated spectroscopic parameters agree with experimental ones where available.