Interface between Nanowire and Oxide

[Deepakgate]

Dear Sir,

I want to make interface between Silicon Nanowire and SiO2. I had tried doing in the Interface section by swapping A and B axis. But SiO2 is not covering the whole surface of Nanowire. I am attaching the figure to make it more clear. Please help in this regard.

[Jess Wellendorff]

Sounds like you want to study oxidized Si nanowire. Would it be easier to first create the SiO2 overlayer (using the Circle selection tool and deleting atoms, in order to carve a hole), and then afterwards insert to Si nanowire into the hole?