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1.25 How do I calculate temperature-dependent elastic constants while relaxing internal degrees of freedom?

This calculation is performed within the ZSISA approximation when what='scf_elastic_constants', what='mur_lc_elastic_constants', or what='elastic_constants_geo'. For a given set of crystal parameters, ions are relaxed to their 0 K equilibrium positions (using frozen_ions=.FALSE.), and phonons-along with the resulting free energy-are computed specifically for that configuration.

For systems where internal relaxations involve only a few degrees of freedom (currently limited to a maximum of 3 ), you can compute the phonons and free energy across a grid of these parameters. The code then minimizes the free energy with respect to these parameters for every set of crystal parameters and for each temperature (FFEM). To move a single atom in one direction: Use stype and related input variables. To utilize internal degrees of freedom: Use stypec and related input variables.


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Next: 1.26 How do I Up: 1. Howtos Previous: 1.24 How do I   Contents
2026-08-13