Parameter definitions for "bravais"
It's probably useful to look first at the special features page.. You may also want to look at one of the general help files, Sliders, or
Graphs.
Inputs
- SLIDERS
- phi: angle in degrees between the coordinate vectors defining the unit cell. (Restricted to values between 0 and 180 degrees.)
- a1: length in angstroms of the horizontal coordinate vector
- a2: length in angstroms of the second coordinate vector
- A1: the projection of the position of the A atoms on the a1 axis in units of a1
- A2: the projection of the position of the A atoms on the a2 axis in units of a2
- atom# ZA: the atomic number of the A atoms. (Restricted to positive integer.)
- radiusA: the radius rA in angstroms of the A atoms. (Restricted to positive or zero.) (The electron density in the atom is the Gaussian exp{-[x^2+y^2]/2*rA^2}; the radius of the circle in the display is three times rA.)
- B1,B2,atom# ZB, and radiusB: define the corresponding values for the B atoms
- TOGGLES
- lattice: (over the left hand display): option to display real-space lattice via cross grids at corners of the unit cells
- atom A: option to display the A atoms and to include their scattering in the calculation of the x-ray diffraction pattern
- atom B: similar option for the B atoms
- lattice: (over the right hand display): option to show the grid of the reciprocal lattice
- diffraction: option to show the diffraction pattern
- show planes: option to display two of the set of (h k) planes in the left hand display and to highlight the corresponding reciprocal lattice point in the right hand display
- BUTTONS
- presets: Takes you to a tear-off menu with which you may select the presets. For more details, see the preset item in the miscellaneous help file.
- configure: There are no configure options for "bravais".
- help: opens the help system which you have already found!
- quit: terminates "bravais".
- ENTRY BOXES
- Miller indices (h) (k): display the Miller indices (h k) of a selected set of lattice planes. Type and enter values here or double click (or right click) near corresponding reciprocal lattice point. (Integers only.)
Outputs
- DISPLAYS
- Left Display: real space showing crystal lattice and/or structure with 0, 1 or 2 atoms per cell
- Right Display: reciprocal space with reciprocal lattice and/or diffraction pattern
- READOUTS
- length: (over left display): length in angstroms of the line segment in real space defined by dragging the cursor in the main display
- alpha: (over left display): angle in degrees with respect to the horizontal of the same line segment
- length: (over right display): length in inverse angstroms of the line segment in reciprocal space defined by dragging the cursor in the main display
- beta: (over right display): angle in degrees with respect to the horizontal of the same line segment