# Latex packages

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## Tensor

\usepackage{tensor}


This package makes it very easy to add mixed upper and lower indices to an object with place holders in the appropriate spot. For example, to emulate the effect of writing

\Gamma^i_{\phantom{i}jk}


\Gamma\indices{^i_{jk}}


The indices are listed in the order listed using a "^" or "_" in front to indicate upper or lower. Phantom spaces are inserted in the correct places. Any number of indices may be used.

A more flexible command is tensor, which has an optional first argument for left indices. For example

\tensor[^a_b]{M}{_c^d}


When the optional argument in the square brackets is dropped the results is the same as \indices.

Both commands have starred version which remove the phantom spaces. This is of course redundant for \indices but is useful for \tensor for the left side indices. This can be used to typeset nuclides, although they have their own dedicated command in the package. The following two commands typeset Carbon-14

\tensor*[^{14}_6]{\mathrm{C}}{}
\nuclide[14][6]{\mathrm{C}}


However, the nuclide command is also available in text mode.