QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Nayab Shiraz on July 1, 2020, 23:36

Title: Unit Cell size
Post by: Nayab Shiraz on July 1, 2020, 23:36

How to select the size of unit cell? I assume enough vacuum around the actual structure is needed. If my results change with change in size of unit cell, do I need to keep increasing the lattice parameters for convergence?

Title: Re: Unit Cell size
Post by: mlee on July 3, 2020, 08:18

If you need to confirm the vacuum size around the actual structure, you can analyze the HatreeDifferencePotential or ElectrostaticDifferencePotential to see the convergence. 

Title: Re: Unit Cell size
Post by: Nayab Shiraz on July 4, 2020, 20:41

Thank you so much. Do you mean that these quantities should not change with further increase in size?

Title: Re: Unit Cell size
Post by: mlee on July 6, 2020, 06:55

You will see the convergence (constant) near the boundary through the HartreeDifferencePotential or ElectrostaticDifferencePotential analysis if it has proper vacuum length.