                       Xtal3.0  INFORMATION
                       ====================


Xtal3.0 is a portable software package for small molecule and macromolecular
crystallographic calculations. A general description of the Xtal concepts is
given by Hall, Stewart and Munn (1980) Acta Cryst. A36, 979-989. Xtal achieves
portability through the use of the preprocessor language ratmac (which is
related to ratfor). The ratmac precompiler converts the Xtal source code into
fortran77. The preprocessor also provides a powerful 'macro editor' facility
which enables machine-specific aspects of the source to be concentrated into a
small library applicable to a wide range of computers. In this way Xtal
achieves portability and machine efficiency. 



Xtal3.0 can be implemented at any computer with the following minimum
specifications: 32-bit integer and real numbers; one Mb of RAM available to the
user (or virtual memory); 30 Mb of disc storage; a Fortran77 compiler; and
access to a 1600 bpi tape drive. 

A customised version is also available for use on PC computers with the 
following minimum specifications: IBM AT or compatable; 536 Kb memory available 
to the user; maths co-processor; MS-DOS or MS-OS/2; MS Fortran-77 Version 5.0; 
20 Mb disc storage.

	 

                         Xtal3.0  Calculations 
                         ---------------------

Xtal3.0 contains programs for 85 different crystallographic calculations.
The function of these programs is given below. The  Xtal System permits a
sequence of calculations to be chained together in a single run. Data is
automatically passed from program to program via an archive binary file.
Most Xtal programs are general and may be applied to crystal structures of
any size or symmetry. Others are intended for macromolecular calculations
(these are flagged below with an asterisk *). For complete details of these
programs read the Xtal3.0 Reference Manual. For your convenience the major
calculations in the system are shown in bold.


	ABSCAL	*applies phi-spin measured absorption corrections
	ABSORB   apply Gaussian, analytical or spherical absorption corrections
	ADDATM   load and check atom site parameters to the binary file
	ADDMUL  *load XENGEN area detector data to the binary file
 	ADDREF   load and reduce reflection data to binary file 
	APMASK  *apply density solvent flattening mask
	ATABLE   prepare table of atomic site parameters for publication
	BAYEST   process intensity data using Bayesian statistics
	BFOURR  *prepare special Fourier coefficients for FOURR 
	BONDAT   generate atom coordinates from molecular geometry
	BONDLA   calculate molecular geometry lengths and angles
	CEDAR	*atom refinement using energy, geometry & dynamics constraints
	CHARGE	 calculates the atomic charge from the electron density
	CIFIO	 reads and generates crystallographic Information File (CIF)
	CONTRS   contour Fourier maps for graphical display
	CONVOL	*generate Fourier coefficients for convolution map
	CRITIQ  *determine the most variable reflections
	CRYLSQ   refine atomic parameters by least-squares
 	DIFDAT   process diffractometer output data (CAD, Nicolet & others)
	EDTBDF	 edit the contents of the binary file
	FC       calculate structure factors 
	FINDKB  *get scale & thermal displacement parameter for protein data
 	FODIFF  *map difference between two fourier maps
	FOGEN    generate a map volume from an asymmetric unit map 
	FOGNU   *generate a map volume from a unit cell map
	FOSTAT  *provide Fourier map density statistics 
	FOURR    map Beevers-Lipson and Fast Fourier Transform 
	GENEV    normalize structure factors	
	GENSIN   generate structure invariant relationships
	GENTAN   estimate phases using generalized tangent procedures
	LATCON	 refine cell constants from measured two-thetas
 	LISTFC   list structure factor data for publication
	LSQPL    calculate least squares planes
	MAKBRK	*generate map data for FRODO input
	MAPLST	 convert FOURR map into list of densities (for Mathematica)
	MEDENS	*maximum entropy phase refinement
	MEFFIT	*restore F values after MEDENS run 
	MERGDS  *select data for addition or replacement
	MERGOB  *merge data from two binary files
	MERUN	*prepare control lines for MEDENS/MEFFIT runs 
	MIR     *apply multiple isomorphous refinement  techniques 
	MKMASK	*make solvent density flattening mask	
	MODEL    search for molecular connections in Fourier map
 	MODHKL   modify reflection data on binary file
	MOGIN	 prepare atom coordinates for MOGLI input
 	MULIST  *list mult.-obs. reflection data
	NEWMAN	 calculate Newman projection data for selected atoms
	NICNAK   process profile data on Nicolet diffractometer tape
 	ORTEP    calculate thermal ellipsoid data for plotting
	PARTN	 determines the contribution of an atom to the density map
	PATSEE	 find mole. fragment using Pat. map and structure invariants
	PEAKIN	 enter pseudo-peaks for processing by modelling software
	PEKPIK   search for density max/min in Fourier map
	PERFAC	 estimate monochromator perfection factor from Irel's
	PHACMP	 compare phases of two sets of structure factors
	PHONYD	 generate phony data for testing statistics
	PIG	 interactive display and manipulation of molecular sites
	PLOT/PLOTX generate graphical outputs of ABSORB, CONTRS, NEWMAN, ORTEP
	PRECED	*load atom data for CEDAR
	PROATM	*loads protein atomic data in the Brookhaven database format
	PROLSQ	*Konnert-Hendrickson restrained structure factor least squares
	PROTIN	*Konnert-Hendrickson restraint builder 
	REFM87	 convert Xtal bdf to SCFS format and reverse
	REMSET  *remove data set  from multiple data set binary file
	REGFE	 calculate crystallographic functions and errors based on ORFEE
	REGWT	 calculates range of least squares weights
	REMSET	*remove a complete data set from the bdf
 	REVIEW   review structure invariant phase relationship statistics
	RFOURR	 reverse Fourier transform.  density -> structure factors
	RIGBOD   transform atom parameters to a different unit cell
	RMAP	 map R-factors to find translated molecular fragment
	RSCAN    scan structure factor agreement by R-factors 
	SCALE1  *places independently measured data sets on same scale
	SHELIN	 input and execute standard Shelx lines to create Xtal bdf
	SIMPEL   estimate phases using symbolic addition  procedure 
	SIMWGT 	*combine Sim weights with Hendrickson-Lattman coefficients
 	SLANT    interpolate slanted map from FOURR map 
	SORTRF   sort and merge reflection data on F, F**2 and I
	STARTX   create binary data file and load symmetry and cell data
	VUBDF	 display the contents of any binary data file 
	VUFILE	 display the contents of any line file 



                        Future Xtal Developments 
                        ------------------------

Additional programs are currently being developed for release in 1992. Xtal is
a collaborative venture involving laboratories with a wide range of
crystallographic interests. Our charges are used principally to distribute and
maintain the system. Financing new software development is primary
responsibility of program author(s). In this way development costs are borne by
collaborating laboratories and agencies so that charges are kept as low as
possible.

Users are encouraged to contribute to the development of Xtal software. New
software must meet the requirements laid down for Reference Manual and undergo
testing at selected sites. The decision to distribute and support a new program
is the responsibility of the Xtal Coordinator. A user wishing to develop
software for general  distribution should first contact the Coordinator to
avoid unnecessary duplication with existing efforts.



                     Xtal Implementation Support 
                     ---------------------------

Detailed implementation instructions are supplied as part of the documentation.
If a user requires additional assistance, either with implementation or
subsequent applications, the following Xtal developers may be contacted.

Asia:  Syd Hall, Crystallography Centre, University of Western Australia,
Nedlands  6009  AUSTRALIA phone:[619] 380-2725  email: syd@crystal.uwa.oz.au  
fax: [619] 380 1118

Europe:  Geoff King, Kristallografi, University of Leuven, Celestijnenlaan
200c, B-3030  Heverlee, BELGIUM   [32] 016-201015  fgeea01@blekul11.bitnet   
fax: [32] 016-201368

America: Jim Stewart, Department of Chemistry, University of Maryland, College
Park, MD  20742, U.S.A.  [1] 301-454-4623  jstew@umd2.umd.edu


This support will normally be provided by fax or e-mail. However, if the
implementor is able to underwrite the expenses, an effort will be made to visit
the site. It must be emphasised, however, that the initial distribution charge
implies no obligation to provide such a service.



                           Xtal3.0 Purchase
                           ----------------

Xtal3.0 is distributed by the Crystallography Centre at the University of
Western Australia. To place an order for Xtal fill out the attached ORDER FORM
and send with a purchase order or an international bank check (in US dollars)
made payable to "XTAL, Crystallography, UWA", to: XTAL Coordinator,
Crystallography, UWA, Nedlands 6009, Australia. Retain a copy of the order for
future reference. An Xtal3.0 tape and documentation will be forwarded by air
post within four weeks of receipt of this order.

 
Initial Purchase

A first-time purchasers of the system receive the Initial Distribution Package.
This includes the tape (or floppies if the PC version is requested) containing
source and implementation software; the Xtal3.0 documentation consisting of a
Reference Manual and a Users Guide and a maintenance agreement covering the
first two year period. The maintenance agreement provides for all software
updates that are distributed during this period, plus periodic Newsletters.


Maintenance Agreement

The purchases of subsequent Xtal releases are handled within the Xtal
maintenance agreement. If this is continued, users will automatically receive
each new release of the system.This only applies if the maintenance does not
lapse. Otherwise an order is treated as a first-time purchase.


Standard and PC Versions

Two versions of Xtal3.0 are available. The standard version supplied on
magnetic tape may be implemented on any 32 bit computer. The PC version is
customised for that application only. If both versions are ordered there is an
additional charge of US$100.


Academic and Industrial Users

There is a price differential between academic and industrial users. Academic
users are educational institutions or government laboratories. Users not in
this category are classed as industrial users.


Conditions of Purchase

The supply of the Xtal System is conditional on the agreement that Xtal
software and documentation be used solely at the site designated on the ORDER
FORM. Neither the software nor documentation may be copied for any use
whatsoever without the explicit written consent of the Xtal Coordinator.
Copyright on Xtal software and documentation is reserved.


Xtal3.0 Charges (in US dollars) [after Oct91]
						Academic	Industrial
Initial Distribution Package	(1 year )	$1000   	$2000
Maintenance Agreement 1992-     (2 years)	$ 500	        $1000

Additional documentation           		
			Reference Manual 	$50 
			User's Guide	        $20




-----------------------------------------------------------------------------


                          Xtal3.0  Order Form
                          -------------------
	

Distribution of Xtal3.0 started in September 1990.  Complete the
information below and accompany this sheet with a purchase order number or
payment by an international bank check. All charges are in US dollars. 
Charges depend on whether you are an academic or an industrial user. If
Xtal is to be used at an educational institution or a government research
laboratory you are classed as an academic user. Otherwise you are classed
as an industrial user. 

					Academic	Industrial

Xtal3.0 Initial Distribution Package*	$1000	        $2000	        $......

Maintenance Agreement* 1992 to 199...	$ 500 /2yr.	$1000 /2yr.	$......


Additional documentation:	Xtal3.0 Reference Manual  $  50	        $......

				Xtal3.0 User's Guide	  $  20 	$......

			  
* Includes 1 Ref. Manual & 1 User's Guide          US dollars 	TOTAL	$......




System should be supplied for:    [  ] standard computer     [  ] PC       
					[  ] both  (add $100)

       For PC version give floppy size and density: [  ] 5.25"   [  ] 3.5"       
                                                    [  ] High    [  ] Double



Future Xtal maintenance agreements to be renewed by autobilling:    

					[  ]  yes         [  ]  no



Name of computer site where Xtal implemented

................................................................



Purchaser's Name and Address	Purchase no.....................

.....................................	Ph:.....................

.....................................	Fx:.....................

.....................................   Em:.....................

.....................................



Declaration: I certify that the above items are to be purchased for installation
             and exclusive use at the above named computer site.


Purchaser's Signature:.....................   Dated:.../..../....


 Send to:    XTAL, Crystallography, UWA, Nedlands 6009, AUSTRALIA.
            or    Fax: 619 380 1118    or    Email: syd@crystal.uwa.oz.au
