3.2. ABSORB: Absorption corrections
| astar [a] | spherical absorption A* values |
| tbar[a] | spherical T values |
| diff[a] | diffractometer description |
| orient[a] | crystal orientation |
| orface [b] | microscope orientation |
| facept[b] | face described by three points |
| face[b] | face described by  , , and distance |
| faceom[b] | face described by ,,  and distance |
| faceml[b] | face described by Miller indices anddistance |
| grid [c] | Gaussian grid description |
| Notes: a. Optional according to mode: diff and orient are mandatory for Gaussian and analytical corrections and are in fact order dependent (the diff line MUST precede the orient line for correct operation) b. Only one of the methods orface, facept, face or faceml may be used to specify the faces of the crystal. c. Used only for the Gaussian integration method. | |
| ABSORB | Option | Code | |||
| absorption coefficient in mm-1 | mu | q | auto[a] | ||
| absorption method | gauss | Gaussian integration | |||
| analyt | analytical method | ||||
| sphere | spherical crystal[b] | ||||
| cylin | cylinder | ||||
| tables | user tables | ||||
| application of absorption | napp | do not apply | |||
| irel | apply to Irel | ||||
| f2rl | apply to F2rel | ||||
| frel | apply to Frel | ||||
| store T on bdf | ntbar | no | |||
| tbar | yes[b] | ||||
| print reflection data | n | print n hkl | 99999 | ||
| limit reflections processed | limit | n | process n hkl | 99999 | |
| dataset specification | dset | n | dataset number | 1 | |
| precision scale factor [c] | pscal | q | scale distance and µ | ||
| crystal plot view on file abs | stereo | stereo view | projection | ||
| radius of crystal in mm | rad | q | |||
| Notes: a. Default is to calculate µ from the cell contents on the bdf. b. If the sphere option is used, do not use the tbar option. c. This option is used to avoid rounding errors for small crystals. | |||||
| astar [a] | 1-19 | values of A* corresponding to 0°,5°, 10°, ..., 90° | |
| Notes: a. More than one astar line may be used. | |||
| tbar [a] | 1-19 | values of T corresponding to 0°, 5°, 10°, ..., 90° | |
| Notes: a. More than one tbar line may be used. | |||
| diff [a] | 1 | sense of rotation of the2 circle | c | clockwise | |
| a | anti-clockwise | ||||
| 2 | sense of rotation of the circle | c | clockwise | ||
| a | anti-clockwise | ||||
| 3 | sense of rotation of the circle | c | clockwise | ||
| a | anti-clockwise | ||||
| 4 | sense of rotation of the circle | c | clockwise | ||
| a | anti-clockwise | ||||
| 5 | sense of rotation of the  circle | c | clockwise | ||
| a | anti-clockwise | ||||
| 6 | value of at = 90 degrees | 0 | |||
| 7 | minimum possible (-180 < < 180) | -48 | |||
| 8 | maximum possible (-180 < < 180) | 58 | |||
| Notes: a. See the Diffractometer description in ABSORB for the method to be used in determining the sense of rotation for each diffractometer circle. | |||||
| orient | 1-3 | hkl indices of first orienting reflection | |
| 4 | angle of first orienting reflection
[a] | ||
| 5 | angle of first orienting reflection | ||
| 6-8 | hkl indices of second orienting reflection | ||
| 9 | angle of second orienting reflection | ||
| 10 | angle of second orienting reflection | ||
| Notes: a. Angles in the bisecting mode. (For CAD see Ch. II of the CAD User's Manual.) | |||
| orface [a] | 1-3 | x, y, z coordinates of first point on orienting face | |
| 4-6 | x, y, z coordinates of second point on orienting face | ||
| 7-9 | x, y, z coordinates of third point on orienting face | ||
| Notes: a. If the orface-facept method is used for entering face data, two orface lines must be used. The first contains the coordinates of three points on a plane parallel to the first orienting reflection given on the orient line. The second orface line contains the coordinates of three points on a plane parallel to the second orienting reflection given on the orient line. | |||
| facept | 1-3 | x, y, z coordinates of first point on bounding face | |
| 4-6 | x, y, z coordinates of second point on bounding face | ||
| 7-9 | x, y, z coordinates of third point on bounding face |
| face | 1 | for bounding face (angles in the bisecting mode) | |
| 2 | for bounding face | ||
| 3 | distance to origin from bounding face in mm |