[Pw_forum] units of psi in e-ph coupling matrix element

[Paolo Giannozzi]

On Thu, 2012-02-23 at 17:08 -0500, Ajit Vallabhaneni wrote:

> I am familiar with the equation (1) in that file.
> However, it is still not clear to me how does 'g' 
> has the units of energy (eV or Ry).

the multiplying factor has the dimension of a length,
the matrix element of an energy over a length 
 
>  Is the wave function psi considered unitless ? 

no: \int \psi^* \psi dV is adimensional.

P.
-- 
Paolo Giannozzi, IOM-Democritos and University of Udine, Italy