subroutine creating rid of structure factors

Author: DCoupry

GetStructureFactors.f90

@@ -0,0 +1,21 @@
+subroutine StructureFactors(positions,numbers,Fhkl)
+    real   , intent(in )  :: positions(:,:)
+    integer, intent(in )  :: numbers(:)
+    real   , intent(out)  :: Fhkl(31,31,31,2)
+    integer :: h,k,l
+    complex :: f_hkl
+    real   , parameter :: pi = 3.1415927
+    complex, parameter :: j  = cmplx(0,1)
+    Fhkl = 0.0
+    nat = size(positions,dim=1)
+    do h=-15,15
+        do k=-15,15
+            do l=-15,15
+                f_hkl = dot_product(exp(2.0*j*pi*(h*positions(:,1)+k*positions(:,2)+l*positions(:,3))),numbers)
+                Fhkl(h+16,k+16,l+16,1) = abs(f_hkl)
+                Fhkl(h+16,k+16,l+16,2) = atan2(aimag(f_hkl),real(f_hkl))
+            end do
+        end do
+    end do
+end subroutine
+