how to keep crystal symmetry

[Roc]

Dear Sir,

Is it possible to keep the crystal symmetry (space group) when optimizing the cell (VNL 2017.2) ?   If so, how to edit the script? Thank you very much. 

[Ulrik G. Vej-Hansen]

Unfortunately, that is not possible in 2017.2. In the 2018.06 release we introduced the option of fixing fractional coordinates, and we hope to implement symmetry constraints, as you are requesting, in the 2019.03 release, but it has not been confirmed yet.