ML ISTART
ML_ISTART = [integer]
Default: ML_ISTART = 0
Description: This tag selects the mode of operation (e.g. start from scratch, prediction-only,...) of the machine learning force fields method.
If the machine learning force fields method is enabled via ML_LMLFF = .TRUE., this tag further specifies the mode of operation when VASP is run. The following cases can be selected:
- ML_ISTART = 0: On-the-fly learning is enabled, starting from scratch. Force predictions from the machine learning force field are used to drive the MD simulation. However, if the error estimation performed in each time step indicates a high force error an ab initio calculation is performed instead and the collected energy, forces and stress are used to improve the machine learning force field. Setting ML_ISTART = 0 starts the machine learning force field from scratch. Hence, in the beginning of the MD run there is no force field available and ab initio calculation will happen frequently.
- ML_ISTART = 1: Same as ML_ISTART = 0 but taking into account pre-existing ab initio data. Before the MD run starts the ML_AB file is read and the containing ab initio energies, forces and stresses are used to generate an initial force field. Then, the MD simulation is started with on-the-fly learning enabled.
- ML_ISTART = 2: Prediction only. In this mode the previously trained machine learning force field is read from the ML_FF file. The MD simulation is driven with predictions from the force field only, no ab initio calculations are performed and no learning is executed. The program reads the force field parameters stored in the ML_FF file and executes calculations using the force field only. No learning is executed.
- ML_ISTART = 3: The program reads the training data stored in the ML_AB file and selects new local reference configurations from the training data.
Warning: This feature is experimental!
Related Tags and Sections
ML_LMLFF, ML_W1, ML_WTOTEN, ML_WTIFOR, ML_WTSIF, ML_IALGO_LINREG