Monte Carlo simulation is appreciated as an extraordinary technique to investigate particle physic processes in Radiation Therapy. This task offers a new Virtual Source Model (VSM) based on an innovative reconstruction method to extract energy and angular distribution from the Python phase space output data. Extensive comparisons of dose distributions are performed to evaluate VSM simulation precision. Four squared field configurations extending from 3 x 3 to 20 x 20 cm(2) are chosen for dose calculation to test field size and symmetry influences. To evaluate simulation accuracy, the beam quality parameters (such as D-10 (%), d(m)(ax) (cm), d(80) (cm), and TPR(20/10)) also validation tests (gamma index formalism for 2%/2 mm criteria, Distance To Agreement DTA, and the estimator standard error (epsilon, epsilon(max))) are determined. Good agreement is achieved in terms of beam quality parameters and validation tests for each evaluated beam size, within a computation time of 58 hours and 17 hours on 20 nodes (presents 160 CPUs) of the full simulation and the VSM, respectively. This advanced VSM generated for the Elekta Synergy MLCi2 platform displays an uncomplicated approach. It is a great example of reconstructing different x-ray beams ofvarious linac accelerators to facilitate its integration in cancer treatment.