CHECKPOINT FD: Difference between revisions

Revision as of 15:40, 21 January 2026

   Warning: Not yet released!

This page contains information about a feature that will be available in a future release of VASP. In other words, currently you cannot use it even with the latest version of VASP. The information may change significantly until it is released.

CHECKPOINT = [string]

Description: CHECKPOINT enables a finite differences calculation to be restarted or split up into displacements

Mind: Available as of VASP 6.6.0

Important: This is currently only available for IBRION = 6.

Important: This feature requires HDF5 support.

Phonon (or vibrational) modes can be calculated using finite differences. A series of displacements is made, DFT calculations are performed on each of these, and then the second-order force is computed, and the dynamical matrix is constructed, from which the phonon modes and frequencies are calculated. Using CHECKPOINT (with IBRION = 6), it is possible to restart a calculation that crashed from the last displacement, or split the calculation into individual displacements. The displacements are written to the vaspcheck.h5 file.

CHECKPOINT = CONTINUE

vaspcheck.h5 file is read (if it exists) and the calculation continues where it left off.
Otherwise, vaspcheck.h5 is created and the displacements are written to it. In both cases, the calculation will finish with the complete vaspcheck.h5.
Repeating CHECKPOINT = CONTINUE will perform a single SCF at the equilibrium structure and read the displacements from vaspcheck.h5.
This mode also detects if the calculation is a single VASP calculation or if it was split into separate pieces. If it has been split, all the calculations need to have finished, or an error will be produced.

CHECKPOINT = RESET - (default): Overwrite the vaspcheck.h5 file and start from scratch. The rest is identical to CHECKPOINT = CONTINUE.
CHECKPOINT = LEGACY: Behavior of the code before VASP 6.6.0. No vaspcheck.h5 file is written.
CHECKPOINT = PREPARE

The vaspcheck.h5 file is created (or overwritten) and filled with metadata.
For each displacement, a CONTCAR_disp-N file is written containing the Nth displacement. VASP then stops after one SCF.
To run this displaced calculation, create a directory disp-N, copy across the corresponding CONTCAR_disp-N file into it and rename it to POSCAR. Then run the calculation with CHECKPOINT = SINGLE.

CHECKPOINT = SINGLE: This mode is used to run the individual single-shot VASP calculations produced by CHECKPOINT = PREPARE. This also produces a vaspcheck.h5 file in the corresponding directory that contains the displaced data.

@@ Line 10: / Line 10: @@
 ----
-Phonon (or vibrational) modes can be calculated using [[Phonons from finite differences | finite differences]]. A series of displacements is made, DFT calculations are performed on each of these, and then the second-order force is computed, and the dynamical matrix is constructed, from which the phonon modes and frequencies are calculated. Using {{TAG|CHECKPOINT}} (with {{TAG|IBRION|6}}), it is possible to restart a calculation that crashed from the last displacement. The displacements are written to the {{FILE|vaspcheck.h5}} file.
+Phonon (or vibrational) modes can be calculated using [[Phonons from finite differences | finite differences]]. A series of displacements is made, DFT calculations are performed on each of these, and then the second-order force is computed, and the dynamical matrix is constructed, from which the phonon modes and frequencies are calculated. Using {{TAG|CHECKPOINT}} (with {{TAG|IBRION|6}}), it is possible to [[Construction:Restarting_finite_differences_calculations#Restarting_a_finite_difference_calculation | restart a calculation that crashed]] from the last displacement, or [[Construction:Restarting_finite_differences_calculations#Splitting_a_finite_difference_calculation | split the calculation into individual displacements]]. The displacements are written to the {{FILE|vaspcheck.h5}} file.
 ;{{TAG|CHECKPOINT|CONTINUE}}
@@ Line 16: / Line 16: @@
 *Otherwise, {{FILE|vaspcheck.h5}} is created and the displacements are written to it. In both cases, the calculation will finish with the complete {{FILE|vaspcheck.h5}}.
 *Repeating {{TAG|CHECKPOINT|CONTINUE}} will perform a single SCF at the equilibrium structure and read the displacements from {{FILE|vaspcheck.h5}}.
-*This mode also detects if the calculation is a single VASP calculation or if it was split into separate pieces. If it was split, all the calculations need to have finished or an error is produced.
+*This mode also detects if the calculation is a single VASP calculation or if it was split into separate pieces. If it has been split, all the calculations need to have finished, or an error will be produced.
 ;{{TAG|CHECKPOINT|RESET}} - (default)
 :Overwrite the {{FILE|vaspcheck.h5}} file and start from scratch. The rest is identical to {{TAG|CHECKPOINT|CONTINUE}}.
@@ Line 22: / Line 22: @@
 :Behavior of the code before VASP 6.6.0. No {{FILE|vaspcheck.h5}} file is written.
 ;{{TAG|CHECKPOINT|PREPARE}}
-*The {{FILE|vaspcheck.h5}} file is created (or overwritten) and filled with meta data.
+*The {{FILE|vaspcheck.h5}} file is created (or overwritten) and filled with metadata.
 *For each displacement, a ''CONTCAR_disp-N'' file is written containing the Nth displacement. VASP then stops after one SCF.
 *To run this displaced calculation, create a directory ''disp-N'', copy across the corresponding ''CONTCAR_disp-N'' file into it and rename it to {{FILE|POSCAR}}. Then run the calculation with {{TAG|CHECKPOINT|SINGLE}}.

Revision as of 15:40, 21 January 2026

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