This page gives hints on how to bound a model in multibinit.
When a model is build, it can contains phonons instabilities and may produce a divergence during the dynamics. To avoid such behaviour, multibinit includes an automatic procedure to bound the model.
Multibinit will first generate a set of coefficients with a power range defined by bound_rangePower and keep only the coefficients with even power. Then, the procedure is similar to the fit process with the constrains to only keep positive coefficients. Next, the bounding process will add the new coefficients to the model up to bound_maxCoeff checking if the model is bound in each step of the process.
The First lesson on Multibinit explains how to build a lattice model and to run a dynamics.
Related Input Variables¶
- bound_SPCoupling BOUND Strain Phonon COUPLING coefficients
- bound_anhaStrain BOUND ANHArmonic STRAIN coefficients
- bound_cutoff BOUND CUT OFF
- bound_maxCoeff BOUND MAX COEFFicient
- bound_model BOUND COEFFicient
- bound_rangePower BOUND RANGE POWER
- bound_cell BOUND superCELL size for the molecular dynamics
- bound_step BOUND number of STEP for the molecular dynamics
- bound_temp BOUND TEMPerature for the molecular dynamics (in Kelvin)
Selected Input Files¶