PDF-4 Axiom - Simplified PDF-5+Database

Application field

PDF-4 Axiom - Simplified PDF-5+DatabaseThe standard diffraction cards of the included phases cover a variety of scientific research fields, such asBattery materials, thermoelectric materials, superconducting materials, metal materials, ceramic materials, mineral materials, metal alloys, drugs, polymersWait. The PDF database isMaterials Science, Physics, Chemistry, Geology, Pharmacology, Biology, Inspection and Quarantine, Forensic AppraisalThe database required for scientific research and industrial production.

Collaborative database

ICDD Powders (00) –International Centre for Diffraction Data

ICSD (01) –Fachinformationzentrum Karlsruhe (FIZ) (International Crystal Structure Database)

NIST (03) –National Institute of Standards and Technology, (National Institute of Standards and Technology database)

MPDS (04) –MaterialPhases Data System, Linus Pauling File (LPF, Linus Pauling File)

ICDD Single Crystal Data (05) –International Centre for Diffraction Data (International Diffraction Data Center - Single Crystal)

Overview

Phase identification+quantitative analysis

The ICDD-PDF-4 Axiom database contains both powder diffraction data and single crystal structure data, providing a streamlined version of the PDF-5+database with comprehensive diffraction data.

• Authorization period of 3 years, higher cost-effectiveness;

• 110800+sets of characteristic diffraction data;

• 80700+sets containing atomic coordinate positions;

• Contains common inorganic and organic data;

• Contains all primary data of minerals;

• Contains data retrieval software;

• Authorization for ordering courses for 3, 6, and 9 years;

• Additional authorization at a better price;

• More options: single machine version, multi machine version.

Search method

PDF-4 Axiom - Simplified PDF-5+DatabaseSupports over 80 phase search methods, including research fields, data sources, data quality, periodic table of elements, space groups, crystallographic parameters, compound names, diffraction data, physical properties of materials, and references, providing convenience for users to quickly and accurately search and identify phases.

1. Research field, data source, data quality, periodic table of elements

2. Chemical formula related searches

3. Search by category and functional group

4. Crystallographic parameters and space group search

5. Diffraction data retrieval

6. Reference search

7. PDF Card Number Retrieval

PDF-4 Axiom standard diffraction card provides conventional phase information

The function of a single PDF-4 Axiom standard diffraction card is consistent with PDF-5+, and each card can provideMore than 130 typesInformation, users can quickly and conveniently grasp the overall overview of the material.

1. PDF card number

Each PDF card has its own number, and each PDF card number corresponds to an object. The PDF card number consists of three sets of data and nine digits, XX-XXX-XXXX， The PDF card number for the iron-based superconductor KFe2Se2 is 00-063-0202, where 00 represents the data source, the card comes from ICDD's powder diffraction database, 063 represents the 63rd volume included, and 0202 represents the corresponding number for the PDF card.

2. Diffraction wavelength

In PDF-4+, users can choose X-ray diffraction targets including Cu, Fe, Mo, Co, Cr, Mn, Ag, and user-defined wavelengths, as well as neutron diffraction (fixed wavelength and TOF neutron data) and electron diffraction data.

3. Diffraction data, relative intensity of diffraction peaks, d-I - (hkl) list

Normalize the peak intensity in the PDF card to 1000, and all other diffraction intensities are relative diffraction intensities; The value of the interplanar spacing d corresponding to the three strong lines is in bold font.

In PDF-4 cards, diffraction intensity is divided into fixed slit intensity, variable slit intensity, and integrated diffraction intensity;

If the suffix of the relative intensity I value is m, it indicates that the relative diffraction intensity of other crystal plane diffraction peaks is equal to that of the crystal plane diffraction peak.

Taking the KFe2Se2 compound with PDF card number 00-063-0202 as an example, the information on the PDF card is as follows:

4. Basic phase information in PDF cards

The basic information of the physical phase in PDF cards mainly includes the following points:

1. Status of PDF cardIt is divided into three types: Primary, Alternate, and Deleted;

PrimaryUsually, it indicates that the data included in the PDF card is of good quality and is diffraction data at room temperature;

AlternateOne PDF card among many PDF cards of a certain material does not necessarily indicate poor quality of the included PDF card;

DeletedThe PDF card has an unresolved error and data that has been deleted from the current PDF database. But the card can still be retrieved, making it convenient for users to refer to the data. In general, PDF cards marked as "Deleted" will be replaced by better quality PDF cards.

2. Quality Mark for PDF Cards， The PDF cards published by ICDD are quality marked for all included data worldwide, and each PDF card undergoes different levels of editing for review, editing, and standardization. If there are multiple PDF cards corresponding to the same object, it is generally recommended to choose the card with a higher quality marking level for use.Quality MarkFor the specific definition of each quality mark in, please pay attention to other professional articles of the official account.

3. The temperature and pressure when collecting this cardIt is worth noting that in the process of phase identification, it is necessary to choose a temperature and pressure that are consistent with the experiment. Otherwise, the structure identified by phase identification may be incorrect.

4. The chemical formula, structural formula, atomic ratio, atomic weight ratio, common English name, mineral name, IMA number, CAS number, inclusion time, etc. of the phase.

5. Experimental conditions used for collecting PDF cards

It mainly includes information such as X-ray wavelength, filter, camera radius, internal standard, d-value, intensity, etc.

6. Crystallographic data of phases (Physical, Crystal)

It mainly includes information such as crystal system, space group, cell parameters, cell volume, chemical formula unit number Z, density, F factor, reference strength RIR value I/Ic, R factor, etc.

In general, if the F factor is greater than 15, it is considered that the XRD pattern of the phase is more reliable.

2. The reference intensity I/Ic is the ratio of the integrated intensity of the strong peaks of the test compound and the standard sample corundum when the weight of the test compound and the standard sample corundum is 1:1. The wavelength of X-rays affects the I/Ic value, and most of the X-ray sources used for collecting PDF cards are Cu K α 1 (1.5406 A). If other wavelengths of X-ray sources are used in the experiment, special attention should be paid to the wavelength used to collect the PDF card when analyzing the relative content of the analyte phase. At this time, the I/Ic value in the PDF card may no longer have reference value. If the PDF card corresponds to structural data, JADE standard or JADE Pro software can be used to theoretically calculate the specific I/Ic values of the phase at different wavelengths.

7. Single crystal structure data (Structure)

It mainly includes crystallographic parameters, space group symmetry operations, atomic coordinates, occupancy information, temperature factors, and other information.

8. Categories corresponding to objects

This mainly includes information on the sub field, ore classification, crystal structure prototype, etc.

9. Cross Reference Similar PDF Cards

Display a series of basic information of PDF cards that can be cross referenced with the current PDF card, and indicate the status of the cross referenced PDF card (Primary, Alternate, or Deleted) or the diffraction pattern of the cross referenced PDF card that has a "correlation phase" with the current PDF card. "Correlation phase" refers to the fact that the two have the same space group and molecular formula, and their stoichiometric ratio may change slightly.

10. Reference

Mainly displays the literature information referenced by the current PDF card, and the number of references varies for different PDF cards.

11. Edit Comments

The main display is the comments on the current PDF card, which are from the contributors or ICDD editors of the card. They generally include basic information such as sample synthesis methods, diffraction inclusion conditions, etc. If the quality of the current PDF card is poor, the editor will also indicate the reason. Many people often overlook this information when using PDF cards. In many cases, the editing comments section of PDF cards contains key information about the phase, which can effectively help users make secondary judgments in phase retrieval.

PDF-4 standard diffraction cards provide characteristic phase information (limited to PDF-4 series databases)

In addition to all the content of traditional PDF-2 cards, the PDF-4 series cards also include additional features such as experimental diffraction spectra, electron/neutron diffraction spectra, two-dimensional powder diffraction spectra (2D-XRD), high and low temperature diffraction spectra, in-situ high-pressure diffraction spectra, structural information, bond length and angle, selected area electron diffraction (SAED), electron backscatter diffraction spectra (EBSD), etc.

1. Temperature Series

The PDF-4 series database contains in situ high and low temperature diffraction data of some phases. Through diffraction data at different temperatures, it is easy to search for the thermal expansion properties, phase transitions, and other properties of materials. Taking PDF card number 00-046-1045 SiO2 as an example, the temperature variation range recorded in the PDF-4+database ranges from 10 K to 1813K.

2. Toolbox

In the Toolbox function area, users can customize the wavelength according to their needs, calculate the peak position, Miller index, interplanar spacing, interplanar angle and other information of the phase.

3. Property Sheet for Physical and Chemical Properties

In the PDF-4 series database, some PDF cards (such as battery materials, ion conductor materials, hydrogen storage materials, semiconductor materials, etc.) contain physical property sheets that display additional information about the phase in document form, such as battery materials and ion conductor materials containing conductivity data. Users can click on the Property Sheet icon to automatically generate a document that displays the basic physical properties of the phase, mainly in text and chart formats, and includes relevant references.

Taking single crystal Ge with PDF card number 00-004-0545 as an example, the attached document on the basic physical properties of the phases in its Property Sheet is shown in the following figure:

4. 2D or 3D structural schematic diagram

For organic compounds, the PDF card usually displays a two-dimensional (2D) structural schematic diagram; For inorganic substances, the PDF card usually displays a three-dimensional (3D) structural schematic and a dynamic schematic; For some phases, both 2D and 3D structural diagrams are included in the PDF card. Usually in 2D structural diagrams, C atoms and H atoms are represented in an omitted form, but when there is ambiguity between C atoms and H atoms, the PDF card will specifically label them in the 2D structure. Users can click on the 2D/3D icon to display a schematic diagram of the 2D or 3D structure of the object phase.

Taking C17H12N2O4 with PDF card number 02-094-1952 as an example, click on the 2D/3D icon. The 2D/3D structure diagram is shown below, where the 3D structure is a dynamic diagram. This example only displays the cross-section of one of the static diagrams:

5. Key length and key angle information (Bonds)

In the PDF-4 series database, detailed information such as bond length, bond angle, atomic coordinates, symmetry, interplanar spacing, atomic spacing, and atomic distribution are provided.

6. Selective Electron Diffraction (SAED)

Taking the selected area electron diffraction pattern (SAED) of Ag3S (NO3) with PDF card number 00-065-0110 as an example

7. Electron backscatter diffraction (EBSD)

8. Two dimensional Debye ring

The PDF-4 series database provides a two-dimensional (2D) diffraction ring spectrum of the phase, which is a simulated image. It is assumed that the detector is located in the center position of the incident beam transmission geometry, and the measured phase is randomly oriented microcrystalline particles.

9. Simulated XRD patterns and XRD experimental patterns of pure phase

The PDF-4 series database provides simulated diffraction profiles and raw diffraction data for phases. Using PDF card number 00-063-0202

Taking iron-based superconductor KFe2Se2 as an example:

PDF-4 Axiom 2025 DatabaseIt can also be directly imported into other commonly used search software, such as JADE Pro or JADE Standard, EVA, Highscore, etc., to achieve seamless integration and provide indispensable help for your scientific research!