.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "Xray::Absorption::Chantler 3pm"
.TH Xray::Absorption::Chantler 3pm "2022-06-28" "perl v5.34.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
Xray::Absorption::Chantler \- Perl interface to the Chantler tables
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 2
\&   use Xray::Absorption;
\&   Xray::Absorption \-> load("chantler");
.Ve
.PP
See the documentation for Xray::Absorption for details.
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
This module is inherited by the Xray::Absorption module and provides
access to the data contained in the Chantler tables of anomalous
scattering factors and line and edge energies.
.PP
The data in this module, referred to as \*(L"The Chantler Tables\*(R", was
published as
.PP
.Vb 4
\&  C. T. Chantler
\&  Theoretical Form Factor, Attenuation, and Scattering Tabulation
\&     for Z = 1 \- 92 from E = 1 \- 10 eV to E = 0.4 \- 1.0 MeV
\&  J. Phys. Chem. Ref. Data 24, 71 (1995)
.Ve
.PP
This can be found on the web at
.PP
.Vb 1
\&  http://physics.nist.gov/PhysRefData/FFast/Text/cover.html
.Ve
.PP
The Chantler data is available on the web at
.PP
.Vb 1
\&  http://physics.nist.gov/PhysRefData/FFast/html/form.html
.Ve
.PP
More information can be found on the personal web page of
C.T. Chantler
.PP
.Vb 1
\&  http://optics.ph.unimelb.edu.au/~chantler/home.html
.Ve
.PP
The data contained in a database file called \fIchantler.db\fR which is
generated at install time from the flat text files of the Chantler data.
The data is stored in a Storable archive using \*(L"network\*(R" ordering.
This allows speedy disk and memory access along with network and
platform portability.
.PP
The required \f(CW\*(C`File::Spec\*(C'\fR, \f(CW\*(C`Chemistry::Elements\*(C'\fR, and \f(CW\*(C`Storable\*(C'\fR
modules are available from \s-1CPAN.\s0
.SH "METHODS"
.IX Header "METHODS"
The behaviour of the methods in this module is a bit different from
other modules used by \f(CW\*(C`Xray::Absorption\*(C'\fR.  This section describes
methods which behave differently for this data resource.
.ie n .IP """get_energy""" 4
.el .IP "\f(CWget_energy\fR" 4
.IX Item "get_energy"
Example:
.Sp
.Vb 1
\&   $energy = Xray::Absorption \-> get_energy($elem, $edge);
.Ve
.Sp
This behaves similarly to the \f(CW\*(C`get_energy\*(C'\fR method of the other
resources.  When using the Chantler data resource, \f(CW$edge\fR can be any of
K, L1\-L3, M1\-M5, N1\-N7, O1\-O5, or P1\-P3.  Line energies are not
supplied with the Chantler data set.  The line energies from the McMaster
tables are used.
.ie n .IP """cross_section""" 4
.el .IP "\f(CWcross_section\fR" 4
.IX Item "cross_section"
Example:
.Sp
.Vb 1
\&   $xsec = Xray::Absorption \-> cross_section($elem, $energy, $mode);
.Ve
.Sp
This behaves slightly differently from the similar method for the
McMaster and Elam resources.  The Chantler tables contain
anomalous scattering factors and the sum of the  coherent and
incoherent scattering cross-sections.  The photo-electric
cross-section is calculated from the imaginary part of the anomalous
scattering by the formula
.Sp
.Vb 1
\&     mu = 2 * r_e * lambda * conv * f_2
.Ve
.Sp
where, \f(CW\*(C`r_e\*(C'\fR is the classical electron radius, lamdba is the photon
wavelength, and conv is a units conversion factor.
.Sp
.Vb 5
\&     r_e    = 2.817938 x 10^\-15 m
\&     lambda = 2 pi hbar c / energy
\&     hbar*c = 1973.27053324 eV*Angstrom
\&     conv   = Avagadro / atomic weight
\&            = 6.022045e7 / weight in cgs
.Ve
.Sp
The \f(CW$mode\fR argument is different here than for the other resources.
The options are \*(L"xsec\*(R", \*(L"f1\*(R", \*(L"f2\*(R", \*(L"photo\*(R", and \*(L"scatter\*(R" telling
this method to return the full cross-section cross-section, the real
or imaginary anomalous scattering factor, just the photoelectric
crosss-section, or just the coherent and incoherent scattering,
respectively.
.Sp
The values for f1 and f2 are computed by linear interpolation of a
semi-log scale, as described in the literature reference.  Care is
taken to avoid the discontinuities at the edges.
.SH "EDGE AND LINE ENERGIES"
.IX Header "EDGE AND LINE ENERGIES"
The Chantler data resource provides a fairly complete set of edge
energies.  Any edge tabulated on the Gwyn William's Table of Electron
Binding Energies for the Elements (that's the one published by \s-1NSLS\s0
and on the door of just about every hutch at \s-1NSLS\s0) is in the Chantler
data resource.  The Chantler data comes with the same, limited set of
fluorescence energies as McMaster.
.SH "BUGS AND THINGS TO DO"
.IX Header "BUGS AND THINGS TO DO"
.IP "\(bu" 4
It would be nice to improve the inter\-/extrapolation near absorption
edges.  As it stands, these tables produce really poor \s-1DAFS\s0 output.
.SH "AUTHOR"
.IX Header "AUTHOR"
.Vb 2
\&  Bruce Ravel, bruce@phys.washington.edu
\&  http://feff.phys.washington.edu/~ravel/software/Absorption
.Ve