# CFOUR_TREAT_PERT

> Specifies whether in a correlated NMR chemical shift calculations all perturbations are treated at once or sequentially. Available option are SIMULTANEOUS (=0) and SEQUENTIAL (=1). The latter is at least preferred for large-scale calculations, as it has less demands on the available disk space.

> - Type: string
> - Possible Values: SIMULTANEOUS, SEQUENTIAL
> - Default: SIMULTANEOUS