First principles molecular dynamics calculations of the mechanical properties of endofullerenes containing noble gas atoms or small molecules

Abstract

The mechanical properties of endofullerenes has been investigated by performing compression tests using finite temperature first principles molecular dynamics calculations. We considered various X@C60 systems, with X a single noble...

Improved Estimates of Host‐Guest Interaction Energies for Endohedral Fullerenes Containing Rare Gas Atoms, Small Molecules, and Cations

“…In the DFT(MN15)/cc‐pVTZ optimized geometry of the complexes, the bond lengths of small molecules (H 2 , HF, H 2 O and NH 3 ) are found to be slightly increased, compared to those of the free molecules, as shown in Table 5. The bond lengths of H−H, H−F, O−H and N−H are increased by 0.0100, 0.0098, 0.0071 and 0.0046 Å, respectively, which coincides well with previous theoretical reports for HF, [14,37,65] H 2 O [22,33,48] and NH 3 [38,75] . On the other hand, there is a slight decrease of 0.001 Å for the C−H bond length of CH 4 inside the cage, when compared to that of free CH 4 , in agreement with the previous predictions [45,47,48] .…”

“…The bond lengths of H−H, H−F, O−H and N−H are increased by 0.0100, 0.0098, 0.0071 and 0.0046 Å, respectively, which coincides well with previous theoretical reports for HF, [14,37,65] H 2 O [22,33,48] and NH 3 [38,75] . On the other hand, there is a slight decrease of 0.001 Å for the C−H bond length of CH 4 inside the cage, when compared to that of free CH 4 , in agreement with the previous predictions [45,47,48] . Furthermore, Table 5 lists the stretching frequencies corresponding to the Y−H bond of the small molecules, with the Δν shifts caused by encapsulation.…”

“…[38,75] On the other hand, there is a slight decrease of 0.001 Å for the CÀ H bond length of CH 4 inside the cage, when compared to that of free CH 4 , in agreement with the previous predictions. [45,47,48] Furthermore, Table 5 lists the stretching ChemPhysChem frequencies corresponding to the YÀ H bond of the small molecules, with the Δν shifts caused by encapsulation. For each complex, we obtained one-two small imaginary frequency values, which indicate that the structures are very close to energy minima and calculation settings such as tighter energy gradient threshold, tighter scf orbital gradient threshold, improved grid accuracy, etc.…”

“…A detailed pedagogic review on endohedral fullerenes was published recently [46] . Some other relevant references to endohedral fullerenes can be found in the literature [47–51] …”

“…[46] Some other relevant references to endohedral fullerenes can be found in the literature. [47][48][49][50][51] The motivation for the present study is to determine reliable interaction energy values for various guest species, including cations, atoms and molecules inside the fullerene cage using the DLPNO-CCSD(T) method. In addition, local energy decomposition (LED) analysis was used to estimate the electrostatic, exchange, and London dispersion components for the abovementioned endohedral fullerene complexes.…”