Exploring the Tl H potential energy surface: A comparative analysis with group 13 systems and experiment.

Area of Science:

• Computational chemistry
• Theoretical inorganic chemistry

Background:

• Thallium chemistry is gaining importance.
• Characterizing simple thallium compounds is valuable.

Purpose of the Study:

• To characterize stationary points on the singlet and triplet thallium hydride (TlH) potential energy surface.
• To determine the relative energies of different TlH isomers.

Main Methods:

• High-level ab initio calculations, including coupled cluster methods (CCSD(T), CCSDT(Q)).
• Geometry optimization and frequency calculations using augmented correlation-consistent basis sets (aug-cc-pwCVQZ-PP, aug-cc-pwCVTZ-PP).
• Extrapolation to the complete basis set limit using the focal point approach and inclusion of zero-point vibrational energy corrections.

Main Results:

• The planar dibridged TlH isomer was found to be the lowest in energy.
• The linear TlH structure was identified as the highest in energy.
• Significant variations were observed when comparing TlH to other Group 13 M H compounds (M = B, Al, Ga, In).

Conclusions:

• The theoretical study provides detailed energetic and structural information for TlH isomers.
• Discrepancies between theoretical predictions and experimental data for thallium hydride were identified.