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QuantumATK => General Questions and Answers => Topic started by: Wisam1222 on April 30, 2021, 21:39

Title: lattice parameters
Post by: Wisam1222 on April 30, 2021, 21:39
Dear All
I built some structures by used different lattice parameters, and found that most of the properties change depending on the lattice parameters.
What are the ideal lattice parameters that I can use to build any structure?
Please help me
Title: Re: lattice parameters
Post by: Petr Khomyakov on May 3, 2021, 12:38
There are typically 2 choice (not limited by no means so): measured value or equilibrium value calculated with a particular Calculator using OptimizeGeometry, https://docs.quantumatk.com/manual/Types/OptimizeGeometry/OptimizeGeometry.html, https://docs.quantumatk.com/tutorials/uniaxial_biaxial_stress/uniaxial_biaxial_stress.html. In the latter, the target stress should be set to zero to get an equilibrium lattice parameter.

In some cases, one may want to strain crystal structure to match it to another material, see https://docs.quantumatk.com/tutorials/ag_au_interface/ag_au_interface.html.

Note that using measured value would like to mean introducing some strain into the corresponding structure, unless the calculated one is exactly as  the measured one.