Volume 2 Chapter 3 3D-Constrain Sub-menu EXHAUSTIVE

Function

When EXHAUSTIVE is highlighted (the default) then the search will be exhaustive for all crystal fragments which pass all tests imposed by SELECT commands and SPHERES of EXCLUSION or INCLUSION.

When EXHAUSTIVE is not highlighted the search will continue until NFRAG (NUMBER-OF-FRAGS) crystal fragments have been located and which pass all tests imposed by SELECT commands and SPHERES of EXCLUSION or INCLUSION.

The default value of NFRAG is 1 if not set by NUMBER-OF-FRAGS in the 2D-CONSTRAIN sub-menu.

Remarks

In most situations the EXHAUSTIVE and OVERLAP commands are both highlighted. This setting results in the following "home" prompt in the dialogue area:

Search for ALL crystal fragments
OVERLAP of crystal fragments permitted
Select a menu command or TO-BUILD to return to the BUILD menu.

If EXHAUSTIVE is toggled off then the first line of the "home" prompt would be:

```
Search for 1 crystal fragments
```

Ex.1 Consider the structures displayed on the facing page.

Suppose we conduct a survey of the four torsion angles of the 4-membered carbocyclic ring.

If the search is conducted with EXHAUSTIVE and OVERLAP both highlighted then all occurrences of the 4-ring crystal fragment should be located, including those which have atoms in common

(ie. OVERLAP is permitted). The fragments located are:

BHPNPH C51   C61   C71   C11
       C52   C62   C72   C12

BHPNPH C2/c Z = 16 Z' = 2

BILSUK C7    C5    C6    C1
       C7'   C5'   C6'   C1'

BILSUK P21/c Z = 4 two half-molecules per asymmetric unit

BIRGEO C1    C6    C10   C5
       C1    C6    C7    C2
       C2    C7    C8    C3
       C5    C10   C9    C4
       C3    C4    C9    C8

BIRGEO P21/c Z = 4 Z' = 1

BORVOT C1    C10   C11   C12
       C15   C24   C25   C26
       C2    C5    C4    C3
       C16   C19   C18   C17
       C9    C6    C7    C8
       C23   C20   C21   C22

BORVOT Pbca Z = 16 Z' = 2

Ex.2 Consider the structures displayed on the facing page.

Suppose we conduct a survey of the four torsion angles of the 4-membered carbocyclic ring.

If the search is conducted with EXHAUSTIVE highlighted but OVERLAP not highlighted then all occurrences of the 4-ring crystal fragment should be located, excluding those which have atoms in common (ie. OVERLAP is not permitted). The fragments located are:

BHPNPH C51   C61   C71   C11
       C52   C62   C72   C12

BHPNPH C2/c Z = 16 Z' = 2

BILSUK C7    C5    C6    C1
       C7'   C5'   C6'   C1'

BILSUK P21/c Z = 4 two half-molecules per asymmetric unit

BIRGEO C1    C6    C10   C5
       C2    C7    C8    C3

BIRGEO P21/c Z = 4 Z' = 1

BORVOT C1    C10   C11   C12
       C15   C24   C25   C26
       C2    C5    C4    C3
       C16   C19   C18   C17
       C9    C6    C7    C8
       C23   C20   C21   C22

BORVOT Pbca Z = 16 Z' = 2

Ex.3 Consider the structures displayed on the facing page.

Suppose we conduct a survey of the four torsion angles of the 4-membered carbocyclic ring.

If the search is conducted with EXHAUSTIVE not highlighted and OVERLAP not highlighted then only one occurrence of the 4-ring crystal fragment should be located in each entry. The fragments located are:

BHPNPH C51   C61   C71   C11

BHPNPH C2/c Z = 16 Z' = 2

BILSUK C7    C5    C6    C1

BILSUK P21/c Z = 4 two half-molecules per asymmetric unit

BIRGEO C1    C6    C10   C5

BIRGEO P21/c Z = 4 Z' = 1

BORVOT C1    C10   C11   C12

BORVOT Pbca Z = 16 Z' = 2

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Volume 2 Chapter 3 3D-Constrain Sub-menu HIST SCAT .