QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: markmick on May 2, 2016, 23:57

Title: Phonon Bandstructures and "strained" unit cells
Post by: markmick on May 2, 2016, 23:57

I'm unable to create Phonon bandstructures Routes for "strained" unit cells.  I can successfully create them for unstrained poscars based on the Phonon Tutorial.

The PhononBandstructure scripter won't allow Routes beyond G.  I try to type in "G, M, K, G" and the text field prevents me from typing in anything other than G.  This makes sense I suppose, since the symmetry has been altered for strained unit cells.   But is there a work-around? 

Thanks,
Mark

Title: Re: Phonon Bandstructures and "strained" unit cells
Post by: Anders Blom on May 3, 2016, 00:12

If some symmetry is still present, like if you just stretched a hexagonal crystal in C, or you turned a cubic one into tetragonal by uniaxial strain, then you just need to convert the cell from UnitCell to the correct Bravais lattice. Use the Builder>Bulk tools>Lattice parameters, but take care that "Keep coordinates" is set to fractional else you may destroy the structure.