Voigt profile

Syntax: y = VOIGT(a,b,c,d)

The Voigt profile function is the convolution integral of a Gaussian and a Lorentzian function. We wish to evaluate

where f(E) is the Gaussian function:   

and g(E) is the Lorentzian:   

Putting

This integral has been evaluated for b > 0 in terms of the complex error function  .

The Voigt function implemented here is:   

  Vector coupling coefficients
  Volume function