*ZPRIME is used to test for a specified Z'-value, ie. the number of formula units per asymmetric unit.

**
CSD Contents**

Z' is defined as Z/m where

- Z is the number of formula units per unit cell
- m is the number of general equivalent positions of the space group

- Z'=2
- implies that the asymmetric unit consists of two formula units

- Z'=0.5
- implies that the asymmetric unit consists of one half-formula unit

- implies that the asymmetric unit consists of one half-formula unit

**
Graphics QUEST3D Procedure**

Select *ZPRIME from the NUMERIC sub-menu and respond to the standard numeric prompts.

**
Basic QUEST Procedure**

**
Ex.**

T1 *ZPRI .EQ. 2

This will register hits for all entries having Z'=2.

**
Related Keywords**

*ZVALUE, *DENC, *DENM, *DENX

Volume 2 Chapter 7 Numeric Sub-menu *ZVALUE.