# Generate tracks' error for OpenMOC

**URL:** <https://openmc.discourse.group/t/generate-tracks-error-for-openmoc/1620>\
**Category:** User Support\
**Created:** [January 4, 2022, 10:39am UTC](https://openmc.discourse.group/t/generate-tracks-error-for-openmoc/1620 "2022-01-04T10:39:49Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![KK\_Lee](https://avatars.discourse-cdn.com/v4/letter/k/779978/32.png) [@KK\_Lee](https://openmc.discourse.group/u/KK_Lee)\
**Post date:** [January 4, 2022, 10:39am UTC](https://openmc.discourse.group/t/generate-tracks-error-for-openmoc/1620/1 "2022-01-04T10:39:49Z")

</div>

Hi, there, when I use the track\_generator to run openmoc,

```auto
track_generator = openmoc.TrackGenerator(openmoc_geometry, num_azim=128, azim_spacing=0.1)
track_generator.generateTracks()

```

the simulation crashed with the error below.

```auto
RuntimeError: Unable to allocate memory needed to generate Tracks.
... Backtrace:
The total height and width of the Geometry must be 
... nonzero for
... Track generation. Create a CellFill which is 
... filled by the 
... entire geometry and bounded by XPlanes and 
... YPlanes to enable 
... the Geometry to determine the total 
... width and height of the 
... model.

```

I just want to varificate the multiGroup cross section on my own geometry. The geometry looks like this:

 ![reactor_xy](https://global.discourse-cdn.com/free1/uploads/openmc/original/2X/6/63885456ce2599b928dc7c3eb106f6aff42cfdb3.png)

my question is how can I fix this and get the openmoc results?

---

<div class="post-metadata">

**Author:** ![paulromano](https://yyz2.discourse-cdn.com/free1/user_avatar/openmc.discourse.group/paulromano/32/486_2.png) [@paulromano](https://openmc.discourse.group/u/paulromano)\
**Post date:** [January 4, 2022, 5:22pm UTC](https://openmc.discourse.group/t/generate-tracks-error-for-openmoc/1620/2 "2022-01-04T17:22:10Z")

</div>

@KK_Lee This forum is for discussion of the OpenMC code, not OpenMOC. I would suggest sending a message to the [OpenMOC user’s group](https://groups.google.com/g/openmoc-users).

---

<div class="post-metadata">

**Author:** ![KK\_Lee](https://avatars.discourse-cdn.com/v4/letter/k/779978/32.png) [@KK\_Lee](https://openmc.discourse.group/u/KK_Lee)\
**Post date:** [January 5, 2022, 1:27am UTC](https://openmc.discourse.group/t/generate-tracks-error-for-openmoc/1620/3 "2022-01-05T01:27:29Z")

</div>

Okay, I will try that, thank you sir.