biomolecule attached to graphene

[Anurag Chaudhury]

Hello,
 in the paper -
R. Chowdhury, S. Adhikari, P. Rees, S.P. Wilks, F. Scarpa
Graphene-based biosensor using transport properties
Phys. Rev. B, 83 (2011), pp. 045401-1–045401-8

the H-atoms of an anthracene molecule are shown to be attached to those of the graphene . Please can anyone clarify what is the type of bonding and how it can be constructed in ATK. Thanks.

[Ulrik G. Vej-Hansen]

In ATK you do not specify the bonding a priori, but if you place the molecule in a certain spatial position, the computational method will then do the calculations based on that. So if you want to do DFT and structural relaxation, then ATK will move the atoms until the forces are below the specified threshold, as calculated with the chosen DFT method. You can then use the different analysis tools to study f.ex. the electron density etc.

[Anurag Chaudhury]

Thanks.