# Bloch boundary conditions

**URL:** https://community.freefem.org/t/bloch-boundary-conditions/280
**Category:** General Discussion
**Created:** [February 28, 2020, 10:59pm UTC](https://community.freefem.org/t/bloch-boundary-conditions/280 "2020-02-28T22:59:52Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![PhyzWiz](https://avatars.discourse-cdn.com/v4/letter/p/a88e57/32.png) [@PhyzWiz](https://community.freefem.org/u/PhyzWiz)
#### Post date: [February 28, 2020, 10:59pm UTC](https://community.freefem.org/t/bloch-boundary-conditions/280/1 "2020-02-28T22:59:52Z")

</div>

Is there a way to implement Bloch (i.e. “twisted” periodic) boundary conditions in FreeFEM?

---

<div class="post-metadata">

### Author: ![frederichecht](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.freefem.org/frederichecht/32/15_2.png) [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [September 1, 2020, 4:07pm UTC](https://community.freefem.org/t/bloch-boundary-conditions/280/2 "2020-09-01T16:07:14Z")

</div>

yes ,

on square

```
mesh Th=square(10,10);
fespace Vh(Th,P1,periodic=[[4,y],[2,1-y]]);

```

…