In:
The Journal of Chemical Physics, AIP Publishing, Vol. 130, No. 10 ( 2009-03-14)
Abstract:
The electronic ground states (X̃Σ+1) of HSiN, HNSi, and the transition state connecting the two isomers were systematically studied using configuration interaction with single and double (CISD) excitations, coupled cluster with single and double (CCSD) excitations, CCSD with perturbative triple corrections [CCSD(T)], multireference complete active space self-consistent field (CASSCF), and internally contracted multireference configuration interaction (ICMRCI) methods. The correlation-consistent polarized valence (cc-pVXZ), augmented correlation-consistent polarized valence (aug-cc-pVXZ) (X=T,Q,5), correlation-consistent polarized core-valence (cc-pCVYZ), and augmented correlation-consistent polarized core-valence (aug-cc-pCVYZ) (Y=T,Q) basis sets were used. Via focal point analyses, we confirmed the HNSi isomer as the global minimum on the ground state HSiNHNSi zero-point vibrational energy corrected surface and is predicted to lie 64.7kcalmol−1 (22640cm−1, 2.81eV) below the HSiN isomer. The barrier height for the forward isomerization reaction (HSiN→HNSi) is predicted to be 9.7kcalmol−1, while the barrier height for the reverse process (HNSi→HSiN) is determined to be 74.4kcalmol−1. The dipole moments of the HSiN and HNSi isomers are predicted to be 4.36 and 0.26D, respectively. The theoretical vibrational isotopic shifts for the HSiN/DSiN and HNSi/DNSi isotopomers are in strong agreement with the available experimental values. The dissociation energy for HSiN [HSiN(X̃Σ+1)→H(S2)+SiN(XΣ+2)] is predicted to be D0=59.6kcalmol−1, whereas the dissociation energy for HNSi [HNSi(X̃Σ+1)→H(S2)+NSi(XΣ+2)] is predicted to be D0=125.0kcalmol−1 at the CCSD(T)/aug-cc-pCVQZ level of theory. Anharmonic vibrational frequencies computed using second order vibrational perturbation theory are in good agreement with available matrix isolation experimental data for both HSiN and HNSi isomers root mean squared derivation (RMSD=9cm−1).
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
2009
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
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