Ab initio pseudopotential study of the fluxional behavior in tetrahydroborate complexes. Many‐body contributions to the energy barriers of NaBH₄, AlH₂BH₄, and GaH₂BH₄

The relative stabilities of the bidentate and tridentate configurations of the complex hydrides NaBH 4 , AlH 2 BH 4 , and GaH 2 BH 4 have been computed both at the Hartree‐Fock and post‐Hartree‐Fock levels using the ab initio pseudopotential method. For both compounds correlation effects favor the configurations with the highest coordination of the metal. The changes with respect to HF results are not very large, so that second‐order perturbative computation of correlation energy is sufficient to give accurate results.