Why the adsorption is on substrate ?

[khariyahA]

Dear Sir, I am referring to this Youtube tutorial link (https://www.youtube.com/watch?v=1k6aYnv0l-8&list=PLkOUx2yxHrqwoIJ_t6fAInqAKn12BpaGL&index=8) from QuantumATK on simulating adsorption of molecules on this material. The picture of my structure model is as attached (see picture adsorption 1). I attempt to use H2O molecules on my heterostructure. My question is why the H2O molecules is on the substrate and not the top layer. I also try to change the surface level and recalculate it back. Now the H2O molecules is below the top layer and still not on the most top layer (see picture adsorption 2). My aim is to have the H2O molecule on the top most layer which in this case is graphene. I appreciate any feedback from the expert. Thank you.

[Habib]

Dear Khariah,

In case of just one H2O molecule (as i can see from your pictures), I suggest selecting the H2O molecule by first clicking on the O atom. Then, press the Control (Ctrl) button and click on the H (hydrogen) atoms. Once the two H atoms and the O atom of H2O are all selected, use the up or down arrow keys on your keyboard to move them accordingly. You can move them to your desired position.

Kind Regards
Habib

[khariyahA]

Thank you sir for the response. I really appreciate it