2. Estimation details
The density functional theory mode is adopted to carry out the
investigation on the potentiality of the 2DNM – Kagome-form of
Phosphorene nanotube (Kagome-PNT) to be used as a fundamental component
in chemi-resistive based sensor to detect the malicious aura producing
bio-molecules – asparagine (amino acid), lactate (VFA) and putrescine
(polyamine). The software package facilitating the scrutinization on
Kagome-PNT is SIESTA [39]. The perfect conformation of the
fundamental component is accomplished by converging the atomic forces on
the constituent phosphorus atoms to 0.001 eV/Å and the energy
convergence is adjusted to 10-6 eV. For the
geometrical optimization, Grimme’s DFT-D2 correction is used while
choosing significance of van der Waals interaction [40]. The
kinetic-energy cut-off is set to 500 eV. The exploration on the
conformational and electronic features of the pure Kagome-PNT and
bio-molecules interacted Kagome-PNT is implemented under the framework
of GGA-B3LYP exchange-correlation functional. The conformational
stability of Kagome-PNT is verified using the formation energy. Besides,
bonding and antibonding aspects between Kagome-PNT and target molecules
are studied with regard to Crystal Orbital Hamiltonian Population (COHP)
analysis [41]. The factors Density of states (DOS) spectrum and Band
Structure under electronic features are explored for the pure and
bio-molecules interacted Kagome-PNT after the sampling of Brillouin
zones at 1 x 1 x 25 are finalized. Moreover, double zeta polarization
basis set and a vacuum padding of 16 Å are fulfilled following which the
interaction features namely the binding energy, average energy gap
alteration and Bader charge transfer are gauged.