Fast matrix methods for calculating the relaxation about defects in crystals
M J Norgett, Roger Fletcher · Journal of Physics C Solid State Physics · 1970
The authors present a method for calculating the relaxation about lattice defects which avoids the very many computations of the energy which are usually required in such calculations. The energy of the crystal is minimized using a modified Newton-Raphson method in which the matrix of the second derivatives of the energy with respect to the relaxation coordinates is corrected after each iteration so that very rapid convergence is obtained.