SHELIN originally worked by including the SHELX.insinstruction file inline within the Xtal .datinput stream. To aid and facilitate data exchange, this behaviour is now activated only by use of the old command line option. The new default behaviour is to read external .insand .hklfiles, although thereafter the behaviour is largely as documented below. Any SHELX dummy Q atom sites are now written as peaks to a compid.pekfile. These can then be viewed within the Xtal molecular graphics program PIG.

All Shelx commands and data may be input into SHELIN but only the following commands are used to generate XTAL input data. Shelx commands and data not listed below will be ignored.

TITL       (optional;
the 
TITL header may be
omitted)
CELL       
LATT   (optional if
lattice is primitive noncentrosymmetric)
SYMM   (any number; 
SYMM X,Y,Z is not
entered)
SFAC   (any number;
but no Cromer-Mann coefficients allowed)       
UNIT       (any
number)

The lines CELLto UNIT must be entered first, and in this order. They are used to initialize the STARTX calculation.

HKLF -3 code       
h k l F 
 
F       (reflection
data in either format)

The HKLFline is used to initialize the ADDREF calculation. If codeis blank the format of the reflection data is assumed to be'3I4,2F8.2'. If codeis nonblank the format is assumed to be '3I3,F7.2,F6.2'. The reflection data input sequence is terminated by a reflection with h=k=l=0 or h=k=l=99.

FVAR K              atom-name
sfacN x y z ....       (std. atom line(s))

The FVARline is used to initialize the ADDATM calculation. The parameter K is the Frel scale factor. Both formats of the standard atom lines may be entered in any order (either with an isotropic U (one line) or with anisotropic U's(two lines)). If anisotropic U's are entered, it is assumed that U11 and U22 are on the first line followed by an '='. An ENDline must follow the last atom line, and this ENDmust be the last line in the Shelx sequence.

END

The use of the ENDline in a Shelx sequence has a special meaning for SHELIN. It is assumed to close the SHELIN sequence. Be careful to remove any superfluous ENDlines from the SHELIN file.

SHELIN is a relatively special program within the XTAL System in that it both creates the input data for STARTX (and optionally ADDREF and/or ADDATM ), and then directly initiates the execution of these routines.

The first stage of SHELIN is to read the SHELX commands and data from the standard line file and converts these into the equivalent XTAL control and data lines. These are output to the formatted file shx.Only the selected SHELX commands and data lines described above are interpreted.

The second stage of SHELIN is to redirect the line input stream from the file shx.This means that after the ENDline terminating the SHELIN lines, the nucleus starts to input the generated XTAL lines from shxand these are used to control the XTAL calculations STARTX , ADDREF and ADDATM .

The second last line in the shxfile is the command ' reset inp <ioinp:>'. This command causes the line input stream to be returned to normal line input , so that additional XTAL commands may be executed. It should also be noted that the lines in shxmay also be used in subsequent XTAL applications without having to use the SHELIN sequence.

SHELIN    
TITL IK 9/4 PHOTOREAKTIVES
BUTENOLID RG PBCN 8/88          
CELL 1.54179 15.180 7.413 22.607 90 90 90          
SYMM .5-X,.5 -Y, .5+Z          
SYMM -X, Y, .5-Z   
SYMM .5+X, .5-Y, -Z          
SFAC C H O          
UNIT 128 128 16          
BOND 1          
FMAP 2       L.S. 4          
HKLF -3          
2 0 0 24.99 -7.66 1          
4 0 0 20.51 -6.52 1          
6 0 0 23.06 3.47 1          
8 0 0 19.46 2.48 1          
10 0 0 15.21 1.70 1   
.......          
.......          
6 8 0 -1.95 -0.50 1          
8 8 0 2.28 0.45 1          
99 99 99 0.00 0.00 0          
FVAR 0.81554          
O1 3 0.13876 0.08798 0.50278 11.00000 0.04336 0.06483 =   
0.04712 -0.00264 0.00342 -0.00309          
O2 3 0.13828 0.14520 0.60009 11.00000 0.05341 0.09107 =   
0.05675 -0.01351 0.01645 -0.00162          
C1 1 0.18085 0.12821 0.55575 11.00000 0.05144 0.04701 =   
0.05208 -0.00446 0.00460 -0.00039   
........   
........          
H16A 2 0.44180 0.18390 0.52360 11.00000 0.05000          
H16B 2 0.45100 0.33370 0.57250 11.00000 0.05000          
END   
PIG 

The output line file SHXfor the above example follows:

STARTX       CELL 15.18000 7.41300 22.60700 90.00000 90.00000
90.0000
LATICE C P       
SYMTRY X,Y,Z       
SYMTRY 1/2-X,1/2-Y,1/2+Z       
SYMTRY -X,Y,1/2-Z       
SYMTRY 1/2+X,1/2-Y,-Z       
CELCON C 128       
CELCON H 128       
CELCON O 16       
DATDEF PARENT       
EXPER 1 1.54179       
ADDREF       
HKLIN HKL FREL SIGF RCOD
HKL 2 0 0 24.990 7.660 2       
HKL 4 0 0 20.510 6.520 2       
HKL 6 0 0 23.060 3.470 1       
HKL 8 0 0 19.460 2.480 1       
HKL 10 0 0 15.210 1.700 1
.....       
.....       
HKL 6 8 0 1.950 .500 2       
HKL 8 8 0 2.280 .450 1       
ADDATM       SCALE 1 .81554       
ATOM O1 .13876 .08798 .50278 3.42357 1.00000       
UIJ O1 .04336 .06483 .04712 -.00309 .00342 -.00264       
ATOM O2 .13828 .14520 .60009 4.21708 1.00000       
UIJ O2 .05341 .09107 .05675 -.00162 .01645 -.01351       
ATOM C1 .18085 .12821 .55575 4.06154 1.00000       
UIJ C1 .05144 .04701  .05208 -.00039 .00460 -.00446
.......       
.......       
ATOM H16A .44180 .18390 .52360 3.94784 1.00000       
ATOM H16B .45100 .33370 .57250 3.94784 1.00000       
RESET INP 5
FINISH