Dear Henrique,
You can create a plain text file in BILD format describing the 3D objects and then open it in Chimera (with “open” command or menu: File… Open).  The file format is described here:

<http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/bild.html>

An example file including several 3D arrows is attached.
I hope this helps,
Elaine
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Elaine C. Meng, Ph.D.
UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab
Department of Pharmaceutical Chemistry
University of California, San Francisco


> On Apr 4, 2016, at 6:36 PM, Henrique C. S. Junior <henriquecsj@gmail.com> wrote:
>
> Dear list,
> Magnetic Anisotropy is a directional property and, because of that, it is useful to repreent it as a vector that crosses the molecule.
> Is that a way to add 3D "arrows" (vectors) using Chimera?