An ab Initio Study of the NH2+ Absorption Spectrum
1Fachbereich 9-Theoretische Chemie, Bergische Universitat-Gesamthochschule Wuppertal, Wuppertal, D-42097, Germany
Journal of Molecular Spectroscopy
|February 3, 1998
Summary
This study calculates new potential energy surfaces for the NH2+ ion, including excited states, to predict rotation-vibration and rovibronic energy levels. These calculations aid in simulating and searching for NH2+ absorption spectra.
Area of Science:
- Theoretical Chemistry
- Molecular Spectroscopy
- Quantum Chemistry
Background:
- Previous work predicted NH2+ ground state energies using an older potential energy surface.
- Accurate potential energy surfaces are crucial for understanding molecular behavior and spectra.
Purpose of the Study:
- To compute new ab initio potential energy surfaces for the X, a, and b electronic states of the amidogen ion (NH2+).
- To calculate rotation-vibration and rovibronic energy levels for these states.
- To simulate absorption spectra to aid experimental identification of NH2+.
Main Methods:
- Multireference configuration interaction (MR-CI) level of theory with state-specific CASSCF-optimized molecular orbital bases.
- MORBID Hamiltonian for the X (3)B1 state rotation-vibration energies.
- RENNER Hamiltonian for the a (1)A1 and b (1)B1 states rovibronic energies.
- Ab initio calculation of dipole moment surfaces and transition moment surfaces.
Main Results:
- New potential energy surfaces for the X (3)B1, a (1)A1, and b (1)B1 states of NH2+ were computed.
- Rotation-vibration and rovibronic energy levels were calculated for these electronic states.
- Dipole moment surfaces and the b <-- a transition moment surface were determined.
Conclusions:
- The computed energy levels and transition moments provide a basis for simulating and interpreting NH2+ spectra.
- This work facilitates the experimental search for the NH2+ ion and its electronic transitions.
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