As discussed above, a trial and error is needed to generate optimum pseudopotentials. However, all electron calculation prior to the pseudopotential generation requires a considerable computational time for an atom with a large atomic number. Therefore, it is desirable to reduce the computational time that results of the all electron calculation are stored in a file and skip the all electron calculation when we regenerate pseudopotentials in different parameters. To do this, two keywords, System.UseRestartfile and System.Restartfile, are available. The details are as follows:
For an atom with a large atomic number, all electron calculation requires a considerable computational time. So, it is needed to reduce the computational time, when optimal cutoff radii of pseudopotentials is determined in trial and error. If the keyword, System.UseRestartfile, is specified as YES, a restart file which contains informations of all electron calculation is used in order to skip all electron calculation. If there is no restart file, a restart file is generated in case of System.UseRestartfile=YES.
If System.UseRestartfile=YES, then the name specified by the keyword, System.Restartfile, is refered to as a restart file.