Next: General Remarks on Crystal
Up: THE CRYSTAL DATA FILE
Previous: Input of the Crystal
Subsections
In order to avoid FORTRAN fixed format READ
statements, CCSL contains a number of free format routines.
These routines are used to read information from the Crystal Data.
Each card is read initially as a string of (up
to) 80 characters. These are then interpreted by CCSL
routines like:
- RDINTG
- read next integer ,
- RDREAL
- read next real number,
- RDWORD
- read next word .
We define three types of item to read: integers, reals and words.
An integer is a (possibly signed) sequence of digits.
A real is a (possibly signed) sequence of digits, possibly containing
one decimal point, or possibly containing one slash. The exponential format:
a (possibly signed) sequence of digits, containing
one decimal point followed by an "E" followed by a (possibly signed integer)
is now allowed.
A word is a sequence of characters starting with a letter.
All three items are terminated by a space or the line end;
integers and reals are also
terminated by a comma. Surplus spaces are allowed.
- Integers
- 6 10 -4 99999, 42, 3
- Reals
- 12.34 92 5/12 -6.78904, -3,
, -12.E5
- Words
- Fred Ca14 This-is-one-long-word
- Not integers
- 3. 12/4 -4-3
- Not reals
- 5./12 4.E2.5 67.89*
- Not words
- 1Fred *JIM
Many of the routines in CCSL recognise special words of up to four characters
which are found in the Crystal Data. Some commonly used types are:
- atom-label
- A word used to identify a particular atomic site;
- scattering-factor-label
- A word used to identify a particular form factor;
- CCSL-word
- A word whose meaning is defined within CCSL.
Next: General Remarks on Crystal
Up: THE CRYSTAL DATA FILE
Previous: Input of the Crystal
P.J. Brown - Institut Laue Langevin, Grenoble, FRANCE. e-mail brown@ill.fr