Structure and Properties of the Open-Chain Calcium-Doped Carbon Clusters CaC_n, CaC_n⁺, and CaC_n^- (n = 1−8)

Abstract

A DFT theoretical study of the CaC n, CaC n + , CaC n -(n ) 1-8) open-chain clusters has been carried out using the B3LYP method with both 6-311G(d) and 6-311+G(d) basis sets. For each species several molecular properties such as vibrational frequencies, dipole moments, and rotational constants are reported. For the CaC n open-chain clusters the lowest-lying states correspond to triplet states for n-odd members, whereas in the n-even species the ground states were found to be singlets. Cationic clusters have doublet ground states with the exception of the smallest one, CaC + . In CaC nclusters, except for CaC 3 -, the ground state is alternate between quartets (for n-odd members) and doublets (for n-even members). The incremental binding energy diagrams show a clear odd-even alternation in the cluster stability in both neutral and anionic clusters with their n-even members being more stable than the corresponding n-odd ones, while the parity effects is less pronounced for the cationic clusters. This odd-even alternation was also found for the electron affinities, whereas there is not a clear alternation in the ionization potentials.

Small Carbon Clusters Doped with Early Transition Metals: A Theoretical Study of ScCn, ScCn+, and ScCn- (n = 1−8) Open-Chain Clusters

“…To discuss the relative stability of the ScC n clusters with different sizes, we will employ, as we made in previous works, ,,− the concept of incremental binding energy. Pascoli and Lavendy suggested that this magnitude could be useful for studying this kind of compounds.…”

Odd‐Even Sequence Effect of Surface‐Mediated Peptide Assemblies Observed by Scanning Tunneling Microscopy

“…Odd-even effects in molecular assemblies could described as alteration of assembly structural characteristics associated with the odd or even number of structural units, such as CH 2 group or other moieties. [29][30][31][32][33] Odd-even effects have been observed in the monolayer of packed molecules with odd-even chain-length on various solid surfaces (HOPG, Ag, Au, Al etc.) by using STM.…”

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

“…Prediction and analysis of such exotic structures is now made possible by advances in mathematical modeling and computational tools. The existence of calcium‐doped carbon clusters (CaC n ; n =1–8) and new types of carbides (Ca 2 C and CaC), which are stable at very high pressures, is proved by calculations. It is also demonstrated that high pressures favor various phase transformations .…”