Carbon chains are one-dimensional linear molecules of the generic formula R-(C≡C) n -R connected by sp-hybridized carbon atoms. The H-capped ones, H-(C≡C) n -H, is the simplest form of a variety of end-substituted carbon chains. They are sometimes referred to as polyacetylenes in the literature, which is an error because the polymer with the formula (H-C≡C-H) n actually is polyacetylene, while the exact name of H-(C≡C) n -H should be polyyne.