Numeric Features of the Beilstein Database on STN

Abstract

Beilstein’s handbook of organic chemistry is currently implemented as a database on STN, starting with the first part containing the heterocyclic substances.

It is the intention of this paper to give an overview of the capabilities of this database on STN with special focus on the numeric features. At first, an introduction to the database is presented starting with an outline of the database design. Following, the various possibilities to search and retrieve the documents from the Beilstein database are discussed. In addition to the normal search for the content of a field it is also possible to search for the name of the field, thus offering an alternative way to access the file.

Several new software features are required to support especially the numeric fields of this database. Most numeric properties are associated with an experimental uncertainty, which must be taken into account by the database loading and retrieval software. This new feature is called numeric range search capability. The problem is briefly described together with a possible solution. In general, a numeric interval can be entered as a range with a lower limit and an upper limit. However, many scientists are more familiar with the notation of a measured value and its associated uncertainty. A feature which allows the specification of a range in terms of a value plus/minus a tolerance offers additional user support. Another important function for numeric databases is the conversion of physical units. Especially in the older literature many units are found which are no longer used mainly due to a standardization process. To overcome the difficulties which are inherent to the use of different units, a function is required which allows the user to work with his own set of physical units and lets the software worry about the transformation to the units used in the specific field of this database. At last, some future developments and requirements are outlined.