I wrote a script to generate mesh with different distribution, so when I created the class of a hexagonal distribution, I can get a differents spacing in our cube. the distance e must be equal. here is the part of the distribution script haxagonal.

Code:
class hexDistribute(distributeAlgorithm) :
    def __init__(self, mesh, domain, collDomain) :
        self.mesh = mesh
        self.domain = domain
        self.collDomain = collDomain


    def search(self) :


        bound = round(self.domain.getBound(), 4)*2
        size = round(self.mesh.getOutsideRadius(), 4)


        self.locList = ()


        k = 0
        while 1 :
            z = (2/3)*(6**(1/2))*k*size
            if z > bound-size*2*self.collDomain :
                break
            j = 0
            while 1 :
                y = (3**(1/2))*((j+((k%2/3)%2)))*size
                if y > bound-size*2*self.collDomain :
                    break
                i = 0
                while 1 :
                    x = (2*i + ((j+(k%2))%2))*size
                    if x > bound-size*2*self.collDomain :
                        break
                    loc = Vector((x, y, z)) + Vector((self.collDomain*size - bound/2,self.collDomain*size - bound/2,self.collDomain*size - bound/2))
                    self.locList += (loc,)
                    i += 1
                j += 1
            k += 1
        return self.locList
distance.png

How to modify this class to fix my problem.