# CFOUR_CONTRACTION

> Specifies the contraction scheme used by the integral and integral derivative program. SEGMENTED (=0) uses a segmented contraction scheme; GENERAL (=1) uses a general contraction scheme, and UNCONTRACTED (=2) uses the corresponding uncontracted sets. Note that even for truly segmented basis sets, the integral programs run significantly faster in the GENERAL mode.

> - Type: string
> - Possible Values: SEGMENTED, GENERAL, UNCONTRACTED
> - Default: GENERAL