The smallest possible inner tube diameter in a double walled carbon nanotube is the zero diameter inner tube, in other words, an infinite linear carbon chain. In this work, we present a first principles study of the vibrational properties of the infinite carbon chain, employing a novel linear/exponential scaling scheme based on the intrinsic behavior of the long range force constant couplings in quasi one-dimensional chains. The longitudinal optical Raman active frequency is predicted at 1870-1877 cm-1, in contrast to the widely accepted values in the 2000-2200 cm-1 range. Our results provide further evidence for the assignment of the characteristic Raman peaks near 1850 cm-1 of the recently discovered long linear carbon chains encapsulated inside multi-walled or double walled carbon nanotubes.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics