The key feature of this method is to use a Local Green's Function to study the properties of a complex system with no long range order or posessing partial order. It has been shown, by Wu and his co-workers[K.S. Dy, S.Y. Wu, and T. Spratlin, Phys. Rev. B20, 4237 (1979).], that for a block tri-diagonal matrix, one can obtain exact expressions for diagonal and off diagonal elements. The local density of the states is then simply proportional to the imaginary part of the Green's Function at the locality in question. This method has been successfully used to study vibrational properties of the Au(511) surface, Incommensurate Structures,Alloys, etc. Since the calculation of Green's Function involves inverting matrices, we have developed efficient schemes to invert large matrices. Also, we have developed an efficient recursive relation that eliminates the redundancy in the calculation of the Local Green's Function(LGF). This procedure of calculating the LGF does not have any truncation unlike the traditional method of calculating the LGF via the continued fraction method.