Searching the Standardized Molecular Formula Field

Searches the Standardized Molecular Formula field within the Derwent Chemistry Resource database.

Enter one or more formulas connected with search operators. You can enter complete formulas or partial formulas using wildcards.


About Standardized Molecular Formula

The Standardized Molecular Formula is based on the molecular formula of the compound and, in most cases, is used simply to indicate the ratios of the different fragments. It consists of several molecular formula fragments. The number of occurrences of each fragment is shown, delimited by the * character.

Note the following principles:

  • The SMF is a searchable text field that contains terms based on the molecular formula of each fragment in the structure along with a qualifier to identify its stoichiometry.

  • If the stoichiometry is unknown or variable, no qualifier is stored.

  • The total number of fragments in the compound will be shown by a keyword TOTAL. If any of the fragments have variable stoichiometry then no TOTAL is shown.

  • The total number of different types of fragments in the compound will be shown by a keyword TYPE. If any of the fragments are optional then no TYPE is shown.


Search Examples
  • C14 H26 O2
  • C10 H15 N O
  • H Li*


Search Tip

If you have trouble searching for standardized molecular formulas, try using quotation marks ("") to enclose the search query. This is required if the formula contains special characters. For example:

"c10 h15 n o *1"returns over 70 results.

On the other hand:

c10 h15 n o *1 returns no results because of the asterisk (*) character in the formula.