The incentive to produce the Patterson Peaks tables is the continuing
use of the Patterson method in determining crystal structures. Even though a
variety of powerful direct methods have now been developed and coded into
computer programs, the 60-year-old "F2-series" method [see, for
A. L. Patterson, Phys. Rev. (1934). 46, 372-376;
A. L. Patterson, Z. Krist. (1935). (A)90, 517-542]
has strengths and features which complement those of
direct methods and which encourage its use today.
The Patterson Peaks tables are intended to provide the positions and
multiplicities expected for peaks in Patterson maps, assuming atoms to be in
the general positions or in the special positions or in every possible
combination of two independent sets of positions for all space groups and all
origin and axis choices included in Volume A of International Tables for
Crystallography (1995). The listed peaks are those which constitute a unique
set in the Patterson map for each space group.
The computer program used to prepare the Patterson Peaks tables was adapted
from part of Allan Zalkin's FORDAP Fourier program [Lawrence Berkeley
Laboratory, Berkeley, CA 94720. Personal communication, June, 1974.].
The space group symmetry file used was based on the Enraf-Nonius MolEN
SPACE.ASC file [C. Kay Fair. Personal communication, July 1989.] and was
corrected and extensively augmented [increased in size by a factor of four!]
to include the special positions and the unit cell origin description for each
The Patterson Peaks tables follow the definitions, the page layout, and the
fonts used for the space group tables in Volume A of International Tables for
Crystallography [with permission from the International Union of
Crystallography, personal communication from Philip Coppens, August, 1994] for
all information taken therefrom to aid the reader in recognizing the
information and to acknowledge its source. The Patterson peaks coordinates,
consistent with their being vector quantities, are printed in
italics [as recommended by Theo Hahn to Philip Coppens, July 1994].
The Patterson peaks multiplicities are printed in bold face.
The On-Line Brief Teaching Edition of Patterson Peaks is patterned after
the Brief Teaching Edition of Volume A of International Tables for
Crystallography and includes tables for the same set of space groups and origin
and axis choices. It is hoped that all who use these tables would
omissions, or other problems found in any part of this publication and would
also make suggestions to improve the content and the presentation.
Donald L. Ward
June 4, 1997
East Lansing, MI