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2.1 QUEST3D: Basics


QUEST3D will carry out the following functions:

Encoding the Search Query

All search queries are encoded via the interactive menu system described in Section 2.3, Appendix A and in the various examples. Queries may be divided into two broad types:

Search Fields and Search TEST's

Individual text and numerical fields in the CSD are referred to by search field names in the relevant menus. These are of the form *FIELD and a full list is given in Appendices B and C. A search of an individual field involves either: Each interrogation of an individual *FIELD is referred to as a search TEST, simple examples are: The logical operators that can be used in a numerical comparison are: .eq. (default) .lt. .le. .ge. .gt. A numerical range may be specified by use of n1 - n2.

Searches based on the graphical encoding of a chemical fragment diagram all involve the interrogation of the 2D chemical connectivity field (internally known as *CONN in QUEST3D) and may also involve the use of the associated 3D coordinate data.

Combining Individual Search TEST's to Form the Final Search QUESTion

A complete CSD search often requires that a number of individual search TEST's must be combined to generate the required results. Thus, many individual TEST's may be encoded (limit 200) and these are numbered sequentially (n in the Tn lines above).

When all necessary TEST's have been encoded, the search is initiated from the QUEST sub-menu. All assembled TEST's are displayed for verification and for inclusion (or not) in the final search QUESTION, where the individual TEST's are combined using the logical operators .AND. .OR. and .NOT. Thus the two tests given above could be combined to create the complete QUESTion:

that would locate all papers by Smith in 1978.

Chemical fragment queries are also assigned a TEST number and displayed graphically by the QUEST sub-menu. They may be included in the logical combination(s) of the QUEST instruction in exactly the same manner using their assigned TEST number(s).

TEST's encoded during a QUEST3D session are always available for inclusion in the final QUESTion line, but it is not necessary that all TEST's shall be included in this process.

Use of Search Keys or SCREEN's

Each CSD entry contains a bitmap that records yes/no (bit setting of 1/0) answers to simple questions about that entry, e.g. "Is this entry error-free after CSD checks?", "Does this entry have an R-factor less than 0.075?", "Was the absolute configuration determined for this entry?", "Is this a neutron study?, etc. These bit settings are called search keys or SCREEN's in the CSD.

A total of 155 screens (Appendix D) are encoded for user-selection. SCREEN'ed searches are rapid to set up and run (SCREEN sub-menu called from SEARCH menu). One or more SCREEN's can form a very powerful complete query in their own right, or may be used in combination with normal TEST's to further define a more complex search query.

Specification of Output Files

Any files that may be required for later use by CSD System programs or by external software are specified to QUEST3D via the SEARCH or QUEST menus (see Section 3.3). QUEST3D generates the following file types by default: .jnl produced in all searches, and .fgd, .sum, .tab in 3D searches.

DISPLAY of Hits

Search hits may be examined within one of four DISPLAY menus: All 3D displays can be manipulated interactively with control of atom labelling and options to create crystallographic packing diagrams.

Registering Hits

Search hits may be accumulated in two ways by use of the DISPLAY menus: Each retained hit generates information in the output files created by QUEST3D.


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