In this project, the quantum Monte Carlo method will be used to obtain the structural and electron properties of silicon clusters, and the purpose is to compare the energy in each silicon cluster between the first four structures previously obtained by calculating a functional density theory. We also use the density functional theory approach using the Quantum- Espresso computational software and the quantum Monte Carlo method by the CASINO code for silicon clusters. The importance of choosing the wave function in this calculation is significant, as we improve the wave functions derived from the QE code using the Monte Carlo method. In Monte Carlo, we will use the improved wave function to get the base state energy. The initial calculations of this project are carried out within the frame- work of the density functional theory and using the PWscf computational package. In this computational package, the single-particle equations are obtained using the quasi-potential method and expansion of the wave-wave functions of the capacitance waveforms in terms of flat waves. After solving single-particle equations, structural and electron properties are determined by computing parameters such as energy and .... Therefore, by comparing the calculation of total energy from the two methods of density function theory and Monte Carlo quantum-diffraction, we compare the structures together. If the difference between the results of Monte Carlo and DFT and DFT is discussed, we will investigate the cause of this.