This version includes miscellaneous changes to neutron scattering lengths and to the Demonstration alert.
"Lion" Cursor Support. SingleCrystal now supports the display of window-resizing cursors, as displayed at the window edges and corners under Mac OS X 10.7 "Lion".
Miscellaneous Changes. This version includes a number of minor changes:
"Double Diffraction" Visualization. SingleCrystal can now display systematically-absent reflexions caused by spacegroup symmetry elements (as distinct from lattice type). These might appear in a TEM diffraction pattern, caused by secondary scattering from primary (allowed) reflexions (i.e., "double diffraction").
A new View > Forbidden Reflexions submenu lets you choose which sorts of forbidden reflexions should be shown.
Forbidden reflexions can also be displayed using the Edit > Diffraction Data command.
Faster Diffraction Simulation & Display. Improvements to the intensity calculation result in faster performance for most structures (up to around 100,000 atoms), especially those with atomic displacement parameters. Displaying simulated Laue patterns has also been made much faster.
Improved Support Commands. The Help > Request Technical Support command now assists you by pre-loading important parameters into the support form, including the program name and version, its serial number, plus your operating system name and version.
A new Help > Register SingleCrystal command provides assistance in the registration process, supplying the program name, its serial number, and your operating system to the online registration form.
A "serial number" is now displayed in the "About" screen (SingleCrystal > About SingleCrystal, Mac; Help > About SingleCrystal, Windows). This serial number is unique to your licence, and can be used in place of the licence code, when requesting technical support (please don't forget to specify "Mac" or "Windows" though!).
Improved window closing commands. Three new menu commands have been added to the File menu, for closing one or more windows:
These commands might be useful in presentations or teaching classes, when one needs to rapidly exit the software without "save file" alerts.
Please note that these are dynamic menu items and will appear when holding down the appropriate modifier keys, such as control and/or option.
Miscellaneous Changes. This version includes a number of minor changes and performance tweaks:
Realistic Electron Diffraction. Earlier versions of the program provided a rather idealized representation of electron diffraction, in which it was assumed that the electron beam was perfectly parallel. This is not the case for a real transmission electron microscope, where the beam converges on the crystal to a greater or lesser degree. This has the effect of extending the range of reflexions that can be recorded: the Ewald Sphere is effectively being rocked back and forth, and hence intersects more reciprocal lattice "spikes".
SingleCrystal now lets you set the beam convergence via a new Diffract > Beam Convergence command. You are prompted to enter a convergence (semi-) angle, in degrees. A typical value might be around 1°. As you increase the beam convergence, more reflexions will be observed - particularly for thicker crystals.
Real-Time Convergence Controls. Two new buttons for increasing or decreasing the simulated TEM beam convergence can be added to the toolbar, via the Customize Toolbar command.
Improved Memory Handling. If a minimum number of reflexions had not been specified, or if the current level were too high, the program could crash for some structures. SingleCrystal now attempts a sensible memory allocation and will, if necessary, warn the user about excessive numbers of reflexions - with the option of cancelling this operation.
SingleCrystal is also able to make more efficient use of memory for reflexion data.
Miscellaneous Changes. This version includes a number of minor changes and performance tweaks:
Improved Preferences. The Restore Last-Saved Settings command now correctly restores the settings from the previous program session. The "Save" button in the Preferences dialog has been renamed "Apply" to better describe its operation.
Improved Overlay Tools. When displaying the Ruler, Protractor or Grid overlays (by clicking the corresponding buttons in the toolbar), the Arrow tool is now made active, thereby making it easier to manipulate the overlays right away.
The Ruler and Protractor popup buttons have been subtly updated, to improve readability of the button text when very light colours have been chosen.
Other Changes. This version includes a number of minor bug fixes and other changes:
Core Graphics Architecture
SingleCrystal uses a streamlined Core Graphics architecture, with no legacy dependences. The latest Quartz Extreme technologies are used, in conjunction with window compositing, for smooth, seamless performance.
High-Performance Graphics. New features include gradient fills(*) and multiple image layers for fast, smooth drawing performance: up to 10x faster than the previous program (when showing rendered reflexions in, say TEM mode).
(*) Requires Mac OS X 10.5 "Leopard", or later. Standard graphics are used, for compatibility purposes, on Mac OS X 10.4 "Tiger".
Higher-Resolution Output. Graphics oversampling is used when printing, copying or exporting graphics. In addition, the plot is now scaled to fill the print size.
X-Ray & Neutron Diffraction
SingleCrystal 2 now provides a wide range of diffraction simulations, designed for x-ray and neutron crystallography in the lab or synchrotron, as well as TEM diffraction.
Precession Patterns. SingleCrystal can now simulate the appearance of X-Ray (or neutron) Precession photographs, showing reciprocal lattice sections with smoothly-rendered reflexions. Upper-level sections can easily be viewed, using the View > Set Lattice Layer submenu.
Laue Patterns. SingleCrystal lets you simulate three different kinds of Laue (white-radiation) diffraction patterns: Front-plate, Rear-plate or Cylinder geometries. A redesigned Wavelength dialog lets you specify a wavelength range between minimum and maximum values, with a checkbox for specifying Polarized radiation.
Background Picture Control
SingleCrystal 2 provides a myriad of tools designed to turn the program from a virtual "light box" to a full-scale measurement and manipulation studio.
Open. You can now open pictures in their own windows, without having to also have a simulated pattern open at the same time. Just use the File > Open command, or drag-and-drop a picture onto the Application icon, or drag the image directly into an open SingleCrystal window.
Move. Both observed and simulated diffraction patterns can now be moved relative to the screen centre, using a new Move tool. This is particularly useful when trying to match a simulated pattern with a real image of an observed pattern which is not centred. A new Selection control lets you specify whether to manipulate the Simulated pattern, the background Picture, or both. To cancel any offsets, click the Centre toolbar button, or choose: Picture > Reset Centre.
Zoom. The zoom controls can now be applied to the background picture, letting you take advantage of high-resolution observed diffraction patterns, zooming in to examine detail, perhaps in conjunction with the Move tool.
Rotate. You can now rotate background pictures. This can be done via menu commands, on the Picture menu, or via the Rotate tool (as with Simulated patterns, to rotate the background picture - about the screen Z axis - you will need to hold the shift key down).
Invert. The Picture menu lets you invert the background picture, e.g., turning a negative image into a positive, which can make reflexions easier to spot.
Opacity. You can control the opacity of the background picture (relative to the chosen background colour). Lowering the opacity of the background picture may make the simulated pattern stand out more, thereby making it easier to compare the two.
Measurement & Autoindexing
SingleCrystal's new screen tools let you measure observed diffraction patterns on screen, without having to use other software or an old-fashioned lightbox. Even better, when used in conjunction with a simulated pattern, the new Grid tool lets you calculate the crystal orientation and index your observed pattern. Surely the easiest method of auto-indexing ever devised?!
Ruler. A translucent ruler can be displayed over an observed diffraction pattern, for easy measurement. The ruler can be moved (with the Arrow tool), resized and rotated, using its two control points.
A popup menu, in the central units display, lets you change the ruler units, between pixels, millimetres, centimetres, inches and reciprocal Ångstroms. The number of divisions can be changed, and the average distance between divisions calculated.Readings can be copied to the clipboard. The ruler colour and opacity can also be changed.
To toggle the ruler display, click the Ruler toolbar button, or choose: View > Show Ruler.
Protractor. A translucent protractor can be superimposed over an observed diffraction pattern, letting you measure angles between groups of reflexions. The protractor can be manipulated with the Arrow tool, so you can move, rotate or resize its two arms, via the three circular control points.
A popup menu lets you copy a measured angle to the clipboard, reset the protractor arms to a preset value, or change the colour or opacity. The protractor can also be "locked", using the padlock icon.
To toggle the protractor display, click the Protractor toolbar button, or choose: View > Show Protractor.
Grid. A translucent grid can be superimposed over an observed diffraction pattern, as the basis for auto-indexing (see below). You can move, resize, rotate and shear the grid, using Arrow tool, and the various grid control points (square points for resizing or shearing; circular points for rotating).
Right-clicking on the Grid brings up a contextual menu, with options for changing the number of divisions, setting the grid colour and opacity, and resetting the grid angle to one of various preset values.Information about the grid, including its unit cell dimensions, shortest distances, ratios and angles, can be displayed on screen.
By overlaying the new Grid tool over an observed pattern, you can instantly reveal the crystal orientation by choosing the Calculate Orientation command from the Grid contextual menu, or by using the View > Set View Direction with Grid command. Following autoindexing, indexing results are displayed in a subtitle at the bottom of the window and the grid is updated to show the calculated results. Furthermore, the simulated pattern has its hkl labels automatically shown.
View Calculator. The new View Calculator palette lets you enter three shortest distances measured for an observed pattern (with the option of adding their angles), in order to calculate the view direction for this pattern. This command uses a revised version of the File > Export > Zone Axes command, to give the best match.
Crosshairs. A set of crosshairs can now be displayed, to help align observed diffraction patterns. These can be toggled on or off using the Crosshairs toolbar button, or the View > Show Crosshairs command.
Save Your Work
For the first time, SingleCrystal lets you save all your work - crystallographic data, simulated diffraction pattern, observed pattern, screen measurements, screen tools, stereographic projection and window size/position data - in a single file.
Just drag-and-drop your observed pattern into a new SingleCrystal window and you can save this - together with your screen tools and measurements - in its own session file. The original image is saved in the session file, using lossless compression, so you don't have to keep track of original data. For fast and easy auto-indexing, drag-and-drop a crystal file into the same window, and compare your observed and simulated patterns directly.
The new SingleCrystal session file has default extension, .scdf.
Browse Data
SingleCrystal now lets you browse detailed listings of structural or diffraction data, with the option of exporting your data - with your customized sorting - to a text file.
Diffraction Browser. A new Edit > Diffraction Data command brings up a comprehensive table of diffraction data, including hkl values, d-spacings, structure factor, phase angle and intensity information. You can click the column headings to sort by different categories. Clicking the window's Save button lets you export the resulting table to a text file.
Crystal Editor. The new Edit > Crystal command lets you view your crystallographic data, edit lattice parameters and choose to mark which sites should be used for intensity calculations.
Miscellaneous Features
Gamma Control. SingleCrystal now better mimics the intensity response of traditional film, using a so-called Gamma response curve to map simulated intensity values to a screen greyscale display. Photographic film shows a logarithmic response, involving a power factor, gamma (γ), where: opacity ∝ Iγ. The gamma value can be adjusted using the Diffract > Gamma Correction submenu. Higher gamma values make it easier to show weaker reflexions, in the presence of stronger ones.
Reflexion Colouring. Reflexions can now be colour-coded by wavelength or intensity, in addition to phase angle.
Spot Size Control. Users can now interactively change the size of simulated reflexions, in addition to their saturation - using a pair of (optional) toolbar buttons. (To add these to your toolbar, choose: View > Customize Toolbar, and drag them from the customize sheet onto the toolbar - Mac version).
Minimum d-spacing. Users have the option, in TEM mode, of displaying the minimum d-spacing allowed by the current program settings, in the form of a circular overlay. This option can be toggled using a new View > Show Minimum D-Spacing command.
New Toolbar. SingleCrystal has a sleek new interface, featuring segmented toolbar buttons (Mac version).
Subtitles. Information about screen tools, progress and other operations is now displayed in the form of "subtitles" in the lower part of the Graphics window. This saves taking up valuable space in the Info bar at the bottom of the window.
New cursors. SingleCrystal now uses its own cursors for different tools (e.g., Move, Distance, Angle).
Intelligent Preferences. A full set of preferences is now automatically saved when you quit the program and all your current settings are applied to new windows. As a result, the Preferences dialog can now be much more concise. New commands are provided to reset preferences to the Factory Settings or Last-Saved Settings.
Smart drag-and-drop. Multiple items can be dragged into the same window, resulting in multiple windows being opened, or, in the case of an image plus a crystal file, the contents of the two files being displayed in the same window.
Multiple Wavelength Dialogs. The wavelength dialog adapts to the current diffraction experiment, letting you maintain separate settings for, say, TEM diffraction, compared with Laue or X-ray Precession patterns.
View Direction. The View Direction window now features shortcut buttons for commonly-used view directions.
Arrow-Key Rotation. The simulated pattern and/or observed pattern, can be rotated using the keyboard arrow keys - if the Move tool is currently active.
New Licensing Dialog. SingleCrystal makes it easier for you to enter your licensing information, with real-time licence code checking. Users transferring their licences to another user can opt to clear their licensing data with a new Delete Licence button.
Improved Diffraction Data File. Exported Diffraction Data files now include the reciprocal lattice volume, plus the lattice-type symbol and a list of general equivalent positions.
New Help System. SingleCrystal's online help system has been completely redesigned and rewritten - and now includes an index. Help topics are now more accessible and better presented.