The above similarity search may be repeated with the Tversky search algorithms and the results should be similar. Each option determines similarity slightly differently, so if you don’t get the results you want on one try the others. At this point, you will be able to specify percent similarity and the similarity measure you want to use (Tanimoto, Tversky, or Euclidean). Then select the “Similarity” radio button. To perform this kind of search, draw, convert or upload your structure (see Structure Search Basics for more information). In order to ensure that the results you get are more likely to be relevant, most of the time it is best to limit Similarity Searching to a minimum of 90% similarity. However, it will return compounds which have many motifs in common. Unlike substructure search, it is not limited to compounds which contain the exact substructure you have entered. Similarity searching will return results which are chemically similar to the structure you have entered. For more information, check out Advanced Search. This type of search can be combined with properties search in order to narrow your results. Then select the “Substructure” tab, and click “Search”. Substructure searching will return all results which contain the structure you have entered, including the exact structure you have entered if it is on ChemSpider. Click on the left pane of the Structure tab to activate and select the tools.Ĭlick on Search and on completion of the search, you should either get to the corresponding record (in certain cases where there is no exact mass, you may see a list of results). You can also draw the structure using one of the structure editors available in ChemSpider, we currently provide two HTML 5 editors Ketcher and Elemental, you can select your preferred editors using the tabs. There are also options to Load a structure from a JPEG or GIF image, which will run an OCR process and let you correct any errors before accepting the structure. This is also the way to use any existing structure files you have in a ChemSpider search. You can then upload the file to ChemSpider using the Load button. On completion of the editing of the structure you can Clean Molecule, Accept or Cancel.Īlternatively, you can draw the structure in your favourite drawing package and save it as a mol, sdf, cdx or skc file to your desktop. For example you might want to change the pre-defined stereochemistry of the bonds. MorphineĬlick Accept to accept the structure or Draw Structure to change features of the structure. This tab allows you to enter a chemical name and auto-generate a structure by selecting Convert.Įxample showing how you can use the Convert structure option to generate an editable structure from a name. Select the Convert identifier to structure tab. There are three ways to enter a chemical structure: The Draw Structure tab may be selected(default setting) but this tab may not not be your current default setting. Click on the structure picture to open the ChemSpider Input Chemical Structure dialog. Select the More Searches menu from the top toolbar and choose Structure Search from the dropdown menu. ![]() It will also cover how to construct advanced searches, which can combine substructure or similarity searches with other kinds of search. This page will outline how to perform structure searches to find exact matches, as well as substructure searches and similarity searches. There are lots of different ways that you can input your structure. For example, if you are starting with mm and you know r in mm, your calculations will result with A in mm 2, V in mm 3 and C in mm.ChemSpider supports the use of chemical structures as search queries. ![]() The units are in place to give an indication of the order of the results such as ft, ft 2 or ft 3. Units: Note that units are shown for convenience but do not affect the calculations. A sphere is a set of points in three dimensional space that are located at an equal distance r (the radius) from a given point (the center point). It will also give the answers for volume, surface area and circumference in terms of PI π. This online calculator will calculate the 3 unknown values of a sphere given any 1 known variable including radius r, surface area A, volume V and circumference C.
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