my ($initial_enthalpy, $initial_entropy) 
    = get_initials ($terminal[0], $initial_enths[1], $initial_entros[1]);

sub get_initials {
  my ($terminal, $enths, $entros) = @_;

  my ($initial_entropy, $initial_enthalpy);
  if ( $terminal =~ /^[GC]/) )    {
    return ($enths, $entros);
  }
}

##</code><code>##

my ($initial_enthalpy, $initial_entropy) = $terminal[0] =~ /^[GC]/
    ? ($initial_enths[1], $initial_entros[1])
    : (undef undef);