Lattice dilation near a single hydrogen molecule in an interstitial channel within a nanotube bundle

TL;DR

This study investigates how a single hydrogen molecule affects the lattice dilation of carbon nanotube bundles, revealing minimal dilation and energy increase compared to dense molecular arrangements.

Contribution

It provides new insights into lattice dilation effects caused by a single hydrogen molecule, extending previous work on dense molecular fluids.

Findings

Single hydrogen molecule causes minimal lattice dilation

Dilation is localized near the molecule

Binding energy increase is much smaller for a single molecule

Abstract

We explore the ground state of a single hydrogen molecule within an interstitial channel (IC) of a bundle of carbon nanotubes. A previous (variational) study found that when many molecules are present, comprising a dense fluid, the nanotube lattice is slightly dilated, with a 1% relative increase of lattice constant. Although small, that dilation doubled the binding energy per molecule inside the ICs. Here, in the case of a single particle, the result is an even smaller dilation, localized near the particle, and a much smaller increase of the binding energy.