Second order Jahn-Teller interactions at unusually high molecular orbital energy separations

Area of Science:

• Computational chemistry
• Quantum chemistry
• Solid-state physics

Background:

• Second order Jahn-Teller (SOJT) effects result from interactions between filled and empty molecular orbitals of similar symmetry.
• These effects can induce molecular structural distortions, with distortion magnitude inversely related to the energy gap between interacting orbitals.

Purpose of the Study:

• To calculate valence molecular orbital energies for EH3, HEEH, and H2EEH2 species (E = N, P, As, Sb, C, Si, Ge, Sn).
• To correlate these orbital energies with barriers for planarization or linearization in these molecules.

Main Methods:

• Density functional theory (DFT) methods were employed for molecular orbital energy calculations.
• Correlational analysis was performed between calculated orbital energies and structural distortion barriers.

Main Results:

• Calculated valence molecular orbital energy separations for the studied species.
• Established a correlation between these energy separations and the propensity for structural distortions.

Conclusions:

• The study identified an approximate 12 eV upper limit for energy separation where SOJT effects remain significant.
• This finding suggests that SOJT effects may be more prevalent in chemical and physical systems than previously assumed.