Greek letters and special symbols

A limited number of special characters (such as Greek letters, sub- and superscripts, and a few others) may be indicated in CIF text for typesetting purposes, using the special codes listed below.

Greek letters

In general, the corresponding letter of the Latin alphabet, prefixed by a backslash character. The complete set is:

α Α \a \A alpha
β Β \b \B beta
χ Χ \c \C chi
δ Δ \d \D delta
ε Ε \e \E epsilon
φ Φ \f \F phi
γ Γ \g \G gamma
η Η \h \H eta
ι Ι \i \I iota
κ Κ \k \K kappa
λ Λ \l \L lambda
μ Μ \m \M mu
ν Ν \n \N nu
ο Ο \o \O omicron
π Π \p \P pi
θ Θ \q \Q theta
ρ Ρ \r \R rho
σ Σ \s \S sigma
τ Τ \t \T tau
υ Υ \u \U upsilon
ω Ω \w \W omega
ξ Ξ \x \X xi
ψ Ψ \y \Y psi
ζ Ζ \z \Z zeta

Accented letters

Accents should be indicated by using the following codes before the letter to be modified (i.e. use \'e for an acute e):

\' acute (é) \" umlaut (ü) \= overbar
\` grave (à) \~ tilde (ñ) \. overdot
\^ circumflex (â) \; ogonek \< hacek
\, cedilla (ç) \> Hungarian umlaut \( breve

Other characters

Other special alphabetic characters should be indicated as follows:

\%a a-ring (å) \?i dotless i \&s German "ss" (ß)
\/o o-slash (ø) \/l Polish l (tex2html_wrap120) \/d barred d

Capital letters may also be used in these codes, so an ångström symbol (Å) may be given as \%A.

Superscripts and subscripts should be indicated by bracketing relevant characters with circumflex or tilde characters, thus:

superscripts Csp^3^ for Csp3
subscripts U~eq~ for Ueq

The closing symbol is essential to return to normal text.

Other codes are also recognized by the IUCr software. These are:

\% degree (°) \\times ×
-- dash +- ±
--- single bond -+ tex2html_wrap_inline104
\\db double bond \\square square
\\tb triple bond \\neq tex2html_wrap_inline108
\\ddb delocalized double bond \\rangle tex2html_wrap_inline110
\\sim tex2html_wrap_inline98 \\langle tex2html_wrap_inline112
(N.B. ~  is the code for subscript) \\rightarrow tex2html_wrap_inline114
\\simeq tex2html_wrap_inline100 \\leftarrow tex2html_wrap_inline116
\\infty tex2html_wrap_inline102    

Note that \\db, \\tb and \\ddb should always be followed by a space, e.g. C=C is denoted by C\\db C.

Special and virtual issues

Acta Crystallographica Section C has recently published special issues on

NMR Crystallography (March 2017)

Scorpionates: a golden anniversary (November 2016)

Full details are available on the special issues page.

The latest virtual issue features Coordination polymers, with an introduction by Len Barbour.

What are the 'most read' articles from the recent special issues?

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