Re: mode volume

On May 20, 2008, at 6:05 PM, Mindy Lee wrote:
> If I only want to calculate the energy integral in the air region  
> inside the donut like defect hole how do I define the object? Do I  
> write it in a following way?

To compute the enrgy inside an annulus ("donut") with compute-energy- 
in-objects, there are two ways:

1) compute the energy in the donut+hole, and then compute the energy  
in the hole, and subtract the two numbers.

2) call compute-energy-in-objects with two objects, one for the object  
and one for the hole, where the material for the hole is specified as  
(material nothing).  The hole must be the *second* object (because in  
MPB, later objects always take precedence over earlier ones).  This is  
an undocumented feature.
>
> Another question is when I use (compute-energy-in-objects  
> objects...) and if I choose the object as the entire unit cell, how  
> do I define the object? same way as I set the geometry? And is the  
> result the same as if I use (compute-energy-integral)?

You can just make the object a sphere with infinite radius, for  
example.  But the result should be identical to compute-energy-integral.

Steven