134
I n t e r n a t i o n a l U n i o n of C r y s t a l l o g r a p h y
Notes for Authors
Acta Crystallographica, an international journal belonging
t h e I n t e r n a t i o n a l U n i o n of Crystallography, is
published in yearly volumes of 12 issues. Papers are
accepted in English, French, German a n d Russian on
all branches of crystallography, including new crystallographic apparatus. Papers on those parts of physics and
c h e m i s t r y which have a structural basis or crystallographic application are also accepted. The submission
of a paper is u n d e r s t o o d to imply t h a t the material is
original, t h a t it has not been previously published, a n d
t h a t it is not i n t e n d e d to publish it elsewhere in a n y
language. Besides the results of original research,
occasional review articles are accepted. I n t e r i m accounts
are discussed at the end of these notes.
Articles in English should be s u b m i t t e d to t h e most
convenient of the following Editors: H. LIPSON, R. E.
M u s H , S. MIYAKE, D. P. SHOEMAKER. Articles in French
should be s u b m i t t e d to J. W Y ~ T , in German to H.
JAGODZINSKI, a n d in :Russian to A. J. C. WIT,SON.
A u t h o r s are r e q u e s t e d to give particular a t t e n t i o n to
t h e following points:
to
Manuscripts. Papers should be in the form of widely
spaced {lines at least 8 m m centre to centre) single-sided
typescripts (top copies) on good quality paper, a n d should
conform to the general editorial style of t h e journal.
Clarity for the printer, r a t h e r t h a n elegance, is the
i m p o r t a n t factor: u n c o n v e n t i o n a l usages or possible
ambiguities (for example zero or letter 0, especially
w h e n subscript; indices hkl or hlcl) should be explained
in marginal notes. B a d l y prepared typescripts involve
m u c h editorial work a n d are likely to suffer delay in
publication. Wide spacing of t h e lines of typescript is
i m p o r t a n t , since it is necessary to leave room for editorial
corrections a n d r e a r r a n g e m e n t s ; it is particularly imp o r t a n t to provide p l e n t y of space in the lists of references.
E v e r y manuscript should bear an address sufficient
for postal purposes.
I t i s possible to give quicker consideration to
manuscripts t h a t are s u b m i t t e d in duplicate, but submission in duplicate is not required. The manuscript
will n o t be r e t u r n e d with the proofs; authors should
therefore retain an exact copy.
The q u a n t i t y of material s u b m i t t e d for publication
is such t h a t the u t m o s t brevity of presentation is essential.
Delay a n d editorial correspondence are avoided if authors
check repeatedly w h e t h e r their presentation can be
simplified or a b b r e v i a t e d w i t h o u t loss of essential detail.
Only exceptionally can papers be considered which
exceed the equivalent of about 6000 words. The p r i m a r y
consideration, however, is one of density of information:
often t h e information contained in several related short
papers could have been p r e s e n t e d more concisely in a
single longer paper. Articles i n t e n d e d for publication as
Short Communications should not exceed the equivalent
of about 1000 words.
Nomenclature. Atoms of the same chemical species
w i t h i n an asymmetric u n i t should be distinguished by
an a p p e n d e d arabic n u m e r a l in parentheses. E x a m p l e s
are C(1), C(2) . . . . ; N(1), N(2) . . . . ; Ca(l), Ca(2) . . . . ;
Si(1), Si(2) . . . . ; O(1), 0(2) . . . . . Fully serial n u m b e r i n g ,
for example C(1), C(2) . . . . .
C(18), N(19), N(20) . . . . .
N(24), Ca(25) . . . . m a y be used w h e n more convenient.
Subscripts (C1, C2, C3 etc.) are n o t acceptable, as t h e y
lead to confusion in chemical contexts.
W h e n it is necessary to distinguish crystallographicaUy
equivalent atoms in different a s y m m e t r i c units t h e
distinction should be m a d e by primes superscript to t h e
arabic n u m e r a l ; if t h e n u m b e r of primes exceeds three
the continuation should be b y superscript small r o m a n
figures. E x a m p l e s are C(1), C(I'), C(I"), C(I'"), C(liv),
C(lv), C(lvi) . . . . . Na(3"), etc.
~ ' h e n t h e a s y m m e t r i c u n i t contains only one a t o m
of a chemical species t h e arabic n u m e r a l m a y be omitted,
a n d if distinction of different a s y m m e t r i c units be
required the superscript m a y be a t t a c h e d directly to
the chemical symbol.
Space groups should be designated by t h e H e r m a n n Mauguin symbol, for example Pba2. The n u m b e r assigned
in International Tables for X-ray Crystallography m a y
be a d d e d if desired for reference, for example Pba2
(no. 32). The Schoenflies symbols (for example C~v) are
discouraged. As a check on t h e space-group orientation
the systematic absences should be given explicitly.
A symbol such as 123 or hkl w i t h o u t brackets is
understood to be an X - r a y reflexion, (123) or (hkl)
a plane or set of planes, [123] or [uvw] a direction, and
{hkl} a form. Other bracket notations should be explicitly
defined by the author.
Authors are r e m i n d e d t h a t 'lattice' is a m a t h e m a t i c a l
concept w i t h an exact meaning, a n d should not be used
loosely as a s y n o n y m for 'structure'.
Abstract. E a c h paper, w h e t h e r in English or a n o t h e r
language, should be preceded by an abstract in English
of not more t h a n about 200 words; this abstract should
be suitable for reproduction by abstracting journals
w i t h o u t change of wording, and should therefore m a k e no
reference to tables, diagrams or formulae contained in
the paper. The Guide for the preparation and publicatio~
of synopses, published by UNESCO, is accepted by t h e
I n t e r n a t i o n a l U n i o n of Crystallography as a basis for
its abstracts. Copies are provided by the Co-editors on
request.
No abstract is accepted for Short Communications.
An author in an Italian-, Spanish-, or Portuguesespeaking country m a y in addition give a brief s u m m a r y
in the appropriate language at the end of t h e paper.
Diagrams. Diagrams should be carefully d r a w n in
black ink with the lettering indicated in soft pencil only.
The lettering should be k e p t to a m i n i m u m , a n d l e n g t h y
descriptive m a t t e r should be e m b o d i e d in t h e legend
rather t h a n in the figure. W h e n e v e r possible, related
diagrams (for example, several electron-density projections of the same structure, or electron-density projections and their keys) should be grouped to form a single
figure, as this leads to considerable e c o n o m y in p r i n t i n g ;
INTE1%NATIONAL
UNION
in a n y case, such diagrams should be prepared on t h e
same scale a n d in a uniform style. Fine-scale details
should be avoided as far as practicable, a n d care should
be t a k e n t h a t arrowheads, broken lines, a n d similar
small features are sufficiently bold. E x a m i n a t i o n of
drawings t h r o u g h a reducing lens is of assistance in
judging w h e t h e r a diagram is suitable for reproduction.
Good q u a l i t y reduced photographic copies of diagrams
are perfectly satisfactory for block m a k i n g a n d are easier
to handle t h a n original drawings.
Very large drawings give great difficulties to t h e
printers, a n d even w h e n supplied in cardboard rolls t h e y
are likely to be d a m a g e d in the post or during editorial
procedures. The dimensions of photographs or original
drawings s u b m i t t e d should not be more t h a n a b o u t twice
those intended for t h e finished diagrams. I t is often
convenient to m a k e t h e m a p p r o x i m a t e l y the same size
as the paper on which the m a n u s c r i p t is t y p e d (about
8½"× 11" or 22 e r a × 28 cm). Additional copies for submission to referees are helpful.
P h o t o g r a p h s intended for half-tone reproduction m u s t
be in t h e form of highly glazed prints. Plates on coated
paper are expensive, a n d authors m a y be asked to
contribute to t h e cost. P l a t e s in colour are accepted
only if the entire cost is paid b y the a u t h o r or his organization.
E v e r y figure should have a legend a n d these legends
should be collected together on a separate sheet.
Tables. E v e r y table m u s t be provided w i t h a caption.
Tables of P values, unless v e r y short, can be accepted
for publication only if t h e y are presented in a form
suitable for direct photographic reproduction. For this
purpose t h e y should be v e r y carefully a n d clearly t y p e d
w i t h a dense black ribbon, a n d should be designed to
conform to the shape a n d dimensions of a page of
Acta Crystallographica after a linear reduction of 2:1
or 2~: 1. A n y symbols inserted b y h a n d should be in
black ink. The tables should be t y p e d in single spacing
(not double spacing, as required for manuscripts) w i t h
columns as close together as is reasonably practicable.
Special care should be t a k e n t h a t there are no errors
a n d t h a t the columns are properly aligned. An example
of a well-designed table will be found in Acta Cryst.
(1962), 15, 313. Large tables should be reduced
photographically before submission to a size t h a t can
be handled w i t h o u t risk of damage, as recommended in
the p a r a g r a p h concerning diagrams.
Mathematics. The printing of m a t h e m a t i c s is very
expensive, a n d m a t h e m a t i c a l a r g u m e n t s should be
a b b r e v i a t e d as far as is practicable w i t h o u t loss of clarity.
M a t h e m a t i c a l expressions should generally be w r i t t e n
clearly a n d carefully in ink, unless a special t y p e w r i t e r
is available. Easily confused symbols (such as u, n, h;
X, x, K; v, r, v) m u s t be clearly distinguished. Gothic
letters should be avoided if possible; if used t h e y should
be explained in the margin or elsewhere. ]3old-face
characters should be indicated b y a w a v y underline.
Chemical compounds and minerals. The nomenclature
of chemical compounds a n d minerals is not always
u n a m b i g u o u s to readers in all countries. Authors are
required therefore to quote t h e chemical formulae,
including organic structural formulae when appropriate,
of t h e substances w i t h which their papers deal, a n d
should whenever possible give details of the origin,
OF
CRYSTALLOGRAPHY
135
h e a t t r e a t m e n t , p u r i t y , a n d experimental density. The
t e m p e r a t u r e at which t h e measurements are m a d e is
often relevant, a n d should always be quoted in work w i t h
a n y claim to accuracy. I t m a y often be necessary to give
the atomic weights of isotopes.
I t is generally desirable to include t h e chemical
formulae in the a b s t r a c t a n d in the first p a r a g r a p h of
the paper.
References. 1%eferences should be t y p e d on a separate
sheet in the style used in Acta Crysl~zUographica, a n d
arranged in alphabetical order of authors' names. Care
should be t a k e n t h a t dates a n d the spellings of authors'
names are everywhere consistent, a n d t h a t authors'
initials are given in the bibliography. The abbreviation
'et al.' should be used sparingly, a n d never a t t h e first
m e n t i o n of a paper.
The following is a specimen reference list:
C o ~ N , M. U. ~1935). Rev. Sci. Instrum. 6, 68.
DE Q~-ERV~N, M. (1944). Helv. Phys. Acta, 17, 509.
DES]tPANDE, V. T. & MUDHOLKER, V. M. (1960). Acta
Cryst. 13, 483.
DESn-PANDE, V. T. & SIRDESttMUKH,D. ]3. (1961a). Acta
Cryst. 14, 353.
DESItPANDE, V. W. & SIRDESHMUKH,D. ]3. (1961b). Acta
Cryst. 14, 355.
FRAZER, B. C. (1948). Thesis, A l a b a m a Polytechnic
Institute.
HtmTI~CGTON, H . ]3. (1958). Solid State Physics, 7, 213.
JETTE, E. 1%. & FOOTE, F. (1935). J. Chem. Phys. 3, 605.
JOEL, N. & WOOSTER, W. A. (1960). Acta Cryst. 13, 516.
K~NzIG, W. (1957). Solid State Physics, 4, 150.
KEELING, 1%. O. & PEPIZqSXY, R. (1955). Z. Kristallogr.
106, 236.
LIVINGSTONE, 1%. (1957). Physico Chemical Experiments,
p. 35. New Y o r k : Macmillan.
MAGYAg, H. (1948). Anz. Ost. Akad. Wiss. 85, (12), 166.
MASON, W. P. (1946). Phys. Rev. 69, 173.
MEGAW, H . (1957). Ferroelectricity in Crystals, p. 45.
L o n d o n : Methuen.
TENZER, L., FRAZER, B. C. & PEPINSKY, R. (1958). Acta
Cryst. 11,505.
UBBELOHDE, A. 1%. & WOODWARD, I. (1947). Prec. Roy.
Soc. A, 188, 358.
UEDA, 1%. (1948). J. Phys. Soc., Japan, 3, 328.
WELLS, A. F. (1950). Structural Inorganic Chemistry,
p. 70. Oxford: Clarendon Press.
Computing details. Sufficient information should be
given to p e r m i t the calculations to be repeated, or, if
need be, extended a t a n y subsequent date b y other
workers.
The wavelength or lattice p a r a m e t e r used as a s t a n d a r d
for m e a s u r e m e n t s of cell dimensions should be s t a t e d
explicitly if the accuracy claimed or implied is b e t t e r
t h a n ½ %.
A table of numerical values of Fo a n d Fc should always
a c c o m p a n y a s t r u c t u r a l paper s u b m i t t e d for publication.
I t should preferably be published w i t h t h e paper, b u t
otherwise deposited in a public depository (such as the
L i b r a r y of Congress).
All parameters involved in the final calculation of
structure factors should be stated.
The atomic scattering factors used should be specified
precisely (including corrections for anomalous scattering
if applied).
The weighting scheme adopted a n d the q u a n t i t y
136
INTERNATIONAL
UNION
m i n i m i z e d in least-squares calculations should be specified (including a s t a t e m e n t of a n y reflexions given
zero weight).
The c o m p u t a t i o n a l procedures should be described in
sufficient detail to permit i n d e p e n d e n t evaluation of t h e
correctness a n d reliability of t h e structure analysis.
W h e n absorption, extinction, or a n y special corrections
or scale factors are applied in t h e reduction of t h e
intensity data, t h e m e t h o d a n d formulae used should be
given.
A final a g r e e m e n t index, or reliability factor (R index)
should be quoted, a n d defined w i t h respect to t h e treatm e n t of t h e u n o b s e r v e d reflexions a n d multiplicities.
The correctness of t h e final structure should be checked,
if possible, by a m e t h o d i n d e p e n d e n t of t h e refinem e n t procedure. Thus, least-squares or differentialsynthesis m e t h o d s of refinement should be verified by
difference-Fourier syntheses to ensure t h a t no i m p o r t a n t
parameters have been overlooked.
F o r m a l e s t i m a t e d s t a n d a r d deviations (e.s.d.'s) should
be quoted a n d their basis defined. The significance of
these e.s.d.'s should be discussed in relation to the
computational procedures e m p l o y e d (e.g. diagonal versus
n o n - d i a g o n a l least squares, convergence -acceleration
methods, weighting scheme, finite-series errors a n d
anharmonicity).
The degree of completeness of the refinement calculations should be indicated, for example by giving the
average a n d m a x i m u m p a r a m e t e r shifts as fractions of
t h e e.s.d.'s in the final cycle of computations.
Where corrections for torsional oscillations, etc. are
m a d e t h e molecular parameters before a n d after correction should be given.
All c o m p u t e r programs used in the crystallographic
analysis should be identified, w h e n possible, by publication references to the author of t h e program in t h e b o d y
of t h e text.
Proofs. Unless other instructions are given on the
typescript, proofs of papers will be sent to the first-named
OF CRYSTALLOGRAPHY
author. T h e y should be r e t u r n e d to t h e Technical E d i t o r
(not to t h e publishers) after correction. The Editorial
Board reserves the right to m a k e a charge for alterations
in proof other t h a n t h e correction of printers' errors.
If such alterations are unavoidable, every effort should
be m a d e to substitute words or phrases equal in length
to those deleted.
W h e n reading proofs, authors should check t h a t all
references are complete, as any omission will delay
publication.
A n order form for reprints is sent out w i t h t h e proofs,
a n d should be r e t u r n e d to t h e publishers (not to t h e
Technical Editor). Only reprints specifically ordered will
be supplied; twenty-five will be provided free if ordered.
F u r t h e r copies, w i t h o u t limit in number, m a y be purchased at a price notified on t h e order form. E x c e p t in
very special circumstances, t h e requirements of all
authors and their laboratories should be included in a
single order. Orders, w h e t h e r for free or additional
reprints, can only be carried out if s u b m i t t e d p r o m p t l y .
I n order to reduce publication delays, proofs of Short
Communications will be read by t h e Technical Editor,
a n d will be sent to the authors only if t h e y present
special difficulties. Order forms for reprints will be sent
to the authors in the same way as for papers.
Interim reports on work in progress. The p r i m a r y
purpose of Acta CrystaUographica is to publish final
accounts of original research, a n d it has n e v e r been
t h e i n t e n t i o n of the Editorial Board t h a t i n t e r i m accounts of work in progress should appear in t h e section
'Short Communications'. A l t h o u g h such accounts m a y
be accepted w h e n t h e y concern long-range projects,
authors are requested n o t to s u b m i t t h e m w h e n completion of t h e work m a y reasonably be expected w i t h i n
eighteen m o n t h s .
Short Communications drawing a t t e n t i o n to t h e
crystallographic aspects of work published in detail
elsewhere will be considered on their merits, b u t c a n n o t
be given high priority in publication.
Book Reviews
Works intended for notice in this column should be sent direct to the Editor (A. J. C. Wilson, Department of Physics, University College, Cathays Park, Cardiff, Great Britain). A s far as practicable books will be reviewed in a country different
from that of publication.
The art and science of growing crystals. Edited
b y J . J. GrLMA~. 493 pp. :New Y o r k a n d L o n d o n :
J o h n W i l e y & Sons. Inc., 1963. Price £ 7.10s.
Es ist fiberflfissig, hier zu betonen, welche hervorragende
B e d e u t u n g h e u t e die Kristallziichtung in Wissenschaft
u n d Technik erlangt hat. Die A n w e n d u n g synthetischer
Kristalle (als Oszillatoren, Polarisatoren, Kristallz~ihler,
optische Medien, ttalbleiter, Piezoelektrika, Maser, Laser
usw.) h a t in den letzten 15 J a h r e n eine ungewShnlich
intensive u n d extensive E n t w i c k l u n g erfahren, u n d doch
scheint es so, als stiinde dieser Trend noch a m Beginn.
I n einer solchen Phase der Ausweitung einer wissenschaftlich-technischen Disziplin ist es i m m e r nfitzlich,
die praktischen Fragestellungen m i t ihren theoretischen
u n d experimentellen Grundlagen u n m i t t e l b a r zu konfrontieren. Das ist das wesentliche Anliegen der Monographic The art and science of growing crystals, die m i t
grosser Sachkenntnis yon Prof. J. J. Gilman herausgegeben wurde. Der G r u n d g e d a n k e ist die u n m i t t e l b a r e
Verknfipfung der 'Kristallzfichtung' m i t den wissenschaftlichen Prinzipien der K e i m b i l d u n g u n d des Kristallwachstums.
Das B u c h gliedert sich in vier :Hauptteile: W a c h s t u m
aus der Dampfphase, Kristallisation aus LSsungen u n d
Pr~izipitationen bei Reaktionen, W a c h s t u m aus der
Schmelze u n d Rekristallisation. J e d e r dieser H a u p t t e f l e
wird m i t einem allgemein g r u n d l e g e n d e n Artikel erSffent:
Theorie des Kristallwachstums aus der D a m p f p h a s e
(N. Cabrera, R. V. Coleman), allgemeine Grundlagen der