File Coverage

blib/lib/Chemistry/Isotope.pm

Criterion	Covered	Total	%
statement	25	25	100.0
branch	7	8	87.5
condition			n/a
subroutine	6	6	100.0
pod	2	3	66.6
total	40	42	95.2

package Chemistry::Isotope;

$VERSION = '0.11';
# $Id: Isotope.pm,v 1.3 2005/05/18 23:14:04 itubert Exp $

use strict;
use warnings;
use base qw(Exporter);
our @EXPORT_OK = qw(isotope_mass isotope_abundance);
our %EXPORT_TAGS = (all => \@EXPORT_OK);

my @masses;
my %abundances;

sub isotope_mass {
    my ($A, $Z) = @_;
    read_data() unless @masses;
    $masses[$A]{$Z};
}

sub read_data {
    local $_;
    while () {
        last if /^$/;
        my ($A, $Z, $m) = split;
        $masses[$A]{$Z} = $m;
    }
    while () {
        my ($symbol, $A, $abundance) = split;
        $abundances{$symbol}{$A} = $abundance;
    }
}

sub isotope_abundance {
    my ($symbol) = shift;
    read_data() unless @masses;
    my %ret = %{$abundances{$symbol} || {}};
    \%ret;
}

1;

=head1 NAME

Chemistry::Isotope - Table of the isotopes exact mass data

=head1 SYNOPSIS

    use Chemistry::Isotope ':all';

    # get the exact atomic mass for an isotope
    my $m  = isotope_mass(235, 92); # 235.043923094753

    my $ab_table = isotope_abundance('C');
    while (my ($A, $percent_ab) = each %$ab_table) {
        print "$A\t$percent_ab\n";
    }
    # this should print (the order may vary):
    # 12    98.93
    # 13    1.07

=head1 DESCRIPTION

This module contains the exact mass data from the table of the isotopes.
It has an exportable function, isotope_mass, which returns the mass
of an atom in mass units given its mass number (A) and atomic number (Z); and
a function isotope_abundance which returns a table with the natural abundance
of the isotopes given an element symbol.

The table of the masses includes 2931 nuclides and is taken from
L (G. Audi and A.H. Wapstra, Nucl. Phys. A595,
409, 1995)

The table of natural abundances includes 288 nuclides and is taken from
the Commission on Atomic Weights and Isotopic Abundances report for the
International Union of Pure and Applied Chemistry in Isotopic Compositions of
the Elements 1989, Pure and Applied Chemistry, 1998, 70, 217.
L

=head1 FUNCTIONS

=head2 isotope_mass($A, $Z)

Return the mass for the atom with the given mass number and atomic number,
or undef if the nuclide is not in the data table.

=head2 isotope_abundance($symbol)

Returns a hash reference with the natural abundance information for the
isotopes of a given element. The hash keys are the mass numbers, and the
values are the abundance percentages. For example, isotope_abundance('C')
returns the following structure:

    {
        '13' => '1.07',
        '12' => '98.93'
    };


=head1 VERSION

0.11

=head1 SEE ALSO

L

The PerlMol website L

=head1 AUTHOR

Ivan Tubert-Brohman [e-mail]

=head1 COPYRIGHT

Copyright (c) 2005 Ivan Tubert-Brohman. All rights reserved. This program is
free software; you can redistribute it and/or modify it under the same terms as
Perl itself.

=cut

__DATA__