Design and ab initio vibrational spectroscopy of low dimensional germanium carbide

In this work, we present a systematic investigation of the electronic and stability of germanium carbide GeC under several arrangements ranging from the 0D diatomic molecule and octahedral Ge_xC_y based fullerenes, the 1D (n,0) single & multi-walled zigzag nanotubes, the 2D graphene like structure to the 3D bulk. Multi-reference configuration-interaction (MRCI-F12) computations were carried out to unravel the potential energy surface of the GeC diatomic molecule and their spectroscopic parameters. The most stable configuration is linear with an X³П electronic ground state that is characterized by a stretching mode of 825 cm^-1. For the other forms, DFT based calculations at the B3LYP level was performed for the prediction and the design of their stable low dimensional structures. Mainly, their Raman and IR spectra were simulated using a coupled-perturbed CPKS/HF scheme permitting their experimental identification. Importantly, at the Γ point, no imaginary frequency is recorded in their vibrational spectra that confirm an inherent stability. The trend toward the 2D graphene-like monolayer in the limit of large 1D nanotube diameter is explored through a variety of energetic and structural parameters. The periodic forms were found to exhibit semiconducting behavior with a wide band gap, making them suitable for optoelectronic nanodevices. Overall, the trends of dimensionality reduction in germanium carbide species on their vibrational spectra help to interpret and identify possible experimental spectrum recorded from interstellar medium.