MacLeod Carey, Desmond

The hydrogen storage properties of Ti-doped Bn ((Formula presented.)) clusters are investigated by using the “diatomic deposition method” with further evaluation by density functional theory computations. The results show that TiBn ((Formula presented.)) clusters possess the ability to storage up to four H2 molecules, reaching a mass fraction of 6.12%. Further, the hydrogen release temperature is analyzed by molecular dynamics simulations with a variable temperature. It turns out that the TiB7 and TiB9 clusters release the H2 molecules at T ≲ 700 K, while TiB8 requires higher temperature due to stronger interactions with the H2 molecules, confirmed by the electronic density of states. The size-dependent properties and odd–even nuclearity on the clusters can be useful for applications with controlled temperature. These results serve for further design of novel materials with reversible and controlled hydrogen storage properties based on TiB7/TiB9 motifs. Additionally, new lower-energy isomers for TiB4 and TiB9 clusters were found within the accuracy of the all-electron triple-ζ Slater [slater type orbital (STO)-Triple-zeta basis set(TZP)] basis set.

Recently, P. V. Nhatet al., have discussed and commented on our article (DOI: 10.1039/D0CP04018E) for the case of the most stable structure of Ag15. They have found a new most stable structure (labeled as 15-1) in comparison to the putative global minimum reported by us, which is a four layered 1-4-6-4 stacking structure with aC2vpoint group (15-2). In this reply, we have performed a larger structure search which allowed us to confirm the results of Nhatet al.The results show the existence of multiple isoenergetic isomers with similar structure motifs for the Ag15system, increasing the problem complexity to locate the global minimum. The results in regard to the structure and electronic properties of the new lowest energy structure are discussed.

In the present work, the lowest energy structures and electronic properties of Agn clusters up to n = 16 are investigated using a successive growth algorithm coupled with density functional theory calculations (DFT). In the literature, a number of putative global minimum structures for silver clusters have been reported by using different approaches, but a comparative study for n = 15-16 has not been undertaken so far. Here, we perform a comparative study using the PW91/cc-pVDZ-PP level to more precisely determine the optimal configuration. For Ag15, the most stable configuration is a four layered 1-4-6-4 stacking structure with C2v symmetry. For Ag16 a new most stable form is found with a 1-4-2-5-1-3 stacking structure in the singlet state, slightly more stable than the putative global minimum reported. By means of the electrostatic potential, the new putative global minimum has been found to be more reactive, and the active sites of the clusters were identified and confirmed with the interaction energy. The electronic and vibrational properties are found to be in good agreement with the available experimental data. Theoretical data on the infrared spectra of the clusters is also provided.