Three-term Gaussian Fit To Gaussian Data (python)

I am trying to fit a gaussian data to a specific three-term gaussian (in which the amplitude in one term is equal to twice the standard deviation of the next term). Here is my att

Solution 1:

With the help of friends from scipy-user forum, I tried as initial guess the following:

p0=[V.max(), std_dev, V.max(), 2]

The fit got a lot better. The new fit is as shown

enter image description here

I hope the fit could get better than this.