The periodic table of chemical elements is one of the most recognized tools in science.  As we mark the 150th anniversary of the periodic table, the scientific community has declared 2019 to be “The International Year of the Periodic Table”.  PubChem is celebrating by launching the PubChem Periodic Table and corresponding Element pages.

While PubChem provides each chemical its own page, you can find elements there too.  Such pages are not suited for displaying information specific to elements (such as electronegativity and electron configuration).  The PubChem Periodic Table and Element pages help you navigate the abundant chemical element data available within PubChem, while providing a convenient entry point to explore additional information, such as bioactivities, health and safety data, available in PubChem Compound pages for specific elements and their isotopes.

PubChem Element page content comes from scientific articles and various authoritative data sources, such as the International Union of Pure and Applied Chemistry (IUPAC), National Institute of Standard and Technology (NIST), International Atomic Energy Agency (IAEA), Jefferson Laboratory, and Los Alamos National Lab.

The PubChem Periodic Table provides three distinct views.  Table View is the traditional periodic table any scientist would instantly recognize.  List View provides a summary view, allowing you to see all properties available for each element at once.   Game View, added as an educational feature, helps test your knowledge of element names and symbols.

Clicking an element in the PubChem Periodic Table directs you to the corresponding Element page.  This page presents a wide variety of element information, including atomic properties (electron affinity, electronegativity, ionization potential, oxidation states, electron configuration, etc.) as well as isotopes, history, uses, and, most importantly, information source.  The element page can also be reached directly via URLs that includes atomic number, symbol, or name (all case insensitive).  For example, the following URLs are for the Element page for carbon:

https://pubchem.ncbi.nlm.nih.gov/element/Carbon

https://pubchem.ncbi.nlm.nih.gov/element/C

https://pubchem.ncbi.nlm.nih.gov/element/6

In addition, the data presented in the Periodic Table and Element pages are also available through programmatic access, using PUG-REST and PUG-View.

We’ve redesigned PubChem’s homepage to give you easier access to the information you need, where you need it. The mobile-friendly, responsive design works on the device you want to use. And the streamlined, intuitive interface puts the data you need at your fingertips.

Here are some of the changes you can expect to see at the new PubChem homepage:

The menus at the top of the page and the sidebar have been replaced with a minimal set of important links. These links include “About,” “Blog,” “Submit,” and “Contact.” The “About” link will bring you to the PubChem Docs site, where you can find an exhaustive list of PubChem services and documentation.

In addition, data count and data source statistics have been highlighted. Each also includes a link you can follow to get more information on these statistics.

Finally, we’ve improved PubChem’s search capabilities. The three search boxes for compounds, substances and bioassays have been replaced with a single search box that covers all search types. Search results from the formerly separate search types (compound, substance, and bioassay) have also been integrated into a single search results display. In addition, search in PubChem now directly supports formula and structure search. We have many more details to share with you about the new PubChem search in a separate blog post, so keep your eyes open for that!

We want to know what you think!

PubChem’s new look and feel is a big step forward for PubChem, and we’re excited to share all of the improvements we’re making across PubChem with you!

What’s working well? What’s not? What’s missing? Send an email to pubchem-help@ncbi.nlm.nih.gov

Stay tuned to this blog for future announcements about the roll-out of all the new designs and features coming to PubChem!

We’ve redesigned PubChem’s summary and record pages with a series of updates both behind the scenes and to your own user experience. These changes will make finding the information you’re looking for easier and faster.

Behind the scenes, we’ve changed the way PubChem models and serves information. Most people won’t see these changes, but the changes do allow us to create pages better suited to your needs, faster. If you’re a programmatic user and you need information on how the data model changes affect you, you can find more information in our blog.

To go along with the behind the scenes changes, we’ve redesigned your user experience with an all new look and feel. To begin, we’ve started color-theming our pages to make it easier to recognize what kind of page you’re on. For example, compound pages may have a light blue theme, while substance pages a yellow theme. There will be themes for bioassay and other page types as well.

PubChem Lindane Compound Summary Page

We’ve also looked over volumes of usage data and user feedback to improve page layout and navigation, and many of the changes you’ll see are a direct response to your feedback. For example, the table of contents has been moved and improved. It now appears on the right side of the page, and higher up on the page. Redundant navigational icons are being removed.

Another result of your feedback is that we’re emphasizing chemical safety information in the summary area at the top of the record. We’re also adding thumbnails for all the available structure types of a given compound (for example, 2D, 3D, crystal) to the summary area. In addition, the graphics quality of the compound 3D Conformer interactive model has been significantly improved.

Please note that, due to the number of upgrades we’re making to PubChem’s pages, legacy browsers will no longer be supported. You can find more information about browsers and browser support here:
https://www.ncbi.nlm.nih.gov/home/about/policies/#browsers

We want to know what you think!

PubChem’s new look and feel is a big step forward for PubChem, and we’re excited to share all of the improvements we’re making across PubChem with you!

What’s working well? What’s not? What’s missing? Send an email to pubchem-help@ncbi.nlm.nih.gov

Stay tuned to this blog for future announcements about the roll-out of all the new designs and features coming to PubChem!

PubChem is updating the data model for objects returned by the PUG View server. These objects are used by both programmatic users and by PubChem web pages. PubChem web users will not be directly affected by the data model changes. Programmatic users, however, will need to update the programs that retrieve and interpret data from PUG View. The following major changes are being made to the data model of the PUG View JSON/XML blobs:

1. No more HTML markup within strings; instead, we will have an explicit markup object that separates primary strings from the various markup types.
2. All values are lists, having separate fields for individual values.
3. No more embedded tables in the data blobs.

No more HTML markup within strings.

PubChem is making a major effort to remove all embedded HTML from within the various strings in the data blobs. Such embedded markup is difficult for parsers to deal with when only a plain string is desired. For example, this is the old model:

{
    "StringValue": "Flipo RM: [Are the NSAIDs able to compromising the cardio-preventive efficacy of <a class=\"pubchem-internal-link CID-2244\" href=\"https://pubchem.ncbi.nlm.nih.gov/compound/aspirin\">aspirin</a>?]. Presse Med. 2006 Sep;35(9 Spec No 1):1S53-60.",
    "URL": "https://www.ncbi.nlm.nih.gov/pubmed/17078596"
}

In the new data model, the main string is in plain text, and the URL links (or other types of markup) are separate, with the character location of the markup on the original string indicated by start and length values. For example:

{
    "String": "Flipo RM: [Are the NSAIDs able to compromising the cardio-preventive efficacy of aspirin?]. Presse Med. 2006 Sep;35(9 Spec No 1):1S53-60. [PMID: 17078596]",
    "Markup": [
        {
            "Start": 139,
            "Length": 14,
            "URL": "https://www.ncbi.nlm.nih.gov/pubmed/17078596",
            "Type": "General link"
        },
        {
            "Start": 81,
            "Length": 7,
            "URL": "https://pubchem.ncbi.nlm.nih.gov/compound/aspirin",
            "Type": "PubChem Internal Link",
            "Extra": "CID-2244"
        }
    ]
}

This new format will make it easier for parsers to get at the relevant text data without a lot of programming overhead.  Please note that this removal of embedded HTML also includes escaped entities in HTML. These will instead be represented by a single UTF8 character (for example, “°” à “°”) within the base string.

All values are lists.

In the new PubChem data model, all values are being converted to list types. We’ve done this to avoid the cumbersome necessity for data parsers to have to check separate fields for single values vs. lists. We’ll use JSON format for the following examples, but the XML data model is parallel to the JSON. Here are two examples of the old format:

{
    "ReferenceNumber": 19,
    "Name": "Melting Point",
    "Reference": [
        "PhysProp"
    ],
    "NumValue": 135,
    "ValueUnit": "°C"
}

or

"Information": [
    {
        "ReferenceNumber": 135,
        "Name": "Standard non-polar",
        "NumValueList": [
            1270,
            1315,
            1309,
            1309
        ]
    }
]

In the examples above, note the fields “NumValue” vs. “NumValueList” – this is cumbersome to code against. In the new system, the examples above would look like this, “Number” being used in both cases within a list structure:

{
    "ReferenceNumber": 35,
    "Name": "Melting Point",
    "Reference": [
        "PhysProp"
    ],
    "Value": {
        "Number": [
            135
        ],
    "Unit": "°C"
    }
}

or,

"Information": [
    {
        "ReferenceNumber": 75,
        "Name": "Standard non-polar",
        "Value": {
            "Number": [
                1270,
                1315,
                1309,
                1309
            ]
        }
    }
]

These changes will make it easier to code your data parsers.

No more embedded tables in the data blobs.

The use of embedded tables in the old system made it difficult for programmatic users to extract specific fields from within the table. The format required you to dig down into the rows and cells of the table to try and find the needed value. For example:

"Information": [
    {
        "ReferenceNumber": 182,
        "Name": "Computed Properties",
        "Table": {
            "ColumnName": [
                "Property Name",
                "Property Value"
            ],
            "Row": [
                {
                    "Cell": [
                        {
                            "StringValue": "Molecular Weight"
                        },
                        {
                            "NumValue": 180.159,
                            "ValueUnit": "g/mol"
                        }
                    ]
                }, …

In the new data below, the fields are more explicitly labeled with section names, the same way as other (non-table) values in the data:

{
    "TOCHeading": "Molecular Weight",
    "Description": "Molecular weight or molecular mass refers to the mass of a molecule. It is calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula.",
    "Information": [
        {
            "ReferenceNumber": 120,
            "Name": "Molecular Weight",
            "Value": {
                "Number": [
                    180.159
                ],
                "Unit": "g/mol"
            }
        }
    ]
}

These changes will make it easier to retrieve data from tables without a lot of programming overhead.

PubChem PUG View Lindane Compound JSON data blob fragment

We want to know what you think!

In summary, PubChem’s new data model makes it easier to retrieve the data you need. As the data model is updated and released, you’ll be able to find detailed information on the schema here: https://pubchemdocs.ncbi.nlm.nih.gov/pug-view.

What’s working well? What’s not? What’s missing? Send an email to pubchem-help@ncbi.nlm.nih.gov