internel auxiliary supercell

[Susan]

Hi friends,

I am interested to know that is an internal auxiliary supercell used in ATK calculation? If yes, where can we get information about the internal auxiliary supercell? I searched the .log file but couldn't find information. Could any friend here please help me?

Because this is related to the computation time, and I would like to get a idea of how the internal auxiliary supercell would change if I change the basis-set settings.

Thanks in advance!

Susan

[zh]

"The auxiliary supercell" may be used in the SIESTA code only when one performs the variable-cell geometry optimization.  In a variable-cell geometry optimization, the cell shape and volume may change, so the actual number of k-point generated by a specified k-grid may also change at every optimization step.The use of auxiliary is to keep the consistency of the matrix elements involving orbitals in different cells.

As I understand,  the changes in the basis set setting are not related to the use of the auxiliary supercell.

[Susan]

Thanks zh for your rapid help and detail explainations.

I am very new to these concepts, still a bit confusing. The size of the auxiliary supercell (i.e. how many atoms inside one such supercell) is related to basis-set (for example, cut-off radius), is it?

Thank you!
Susan