I want to know how to apply a periodic boundary condition in material studio using FORCITE module.i have taken an C3S unit cell and geometry optimized it using universal force field, and went to dynamics using NPT ensemble at room temperature i did the run and then went to mechanical properties and the E, G, K values obtained are not matching the journal article i refered i.e K=27.7 G=16.63 and E= 41.57 (the values which he got) but my values are K=2.66 G=0.32 and E=0.95. plz help me in this matter.
I pasting the simulation method he has followed in his journal" Before starting the simulations, it is essential to minimize the energy of structures. The energy minimization process was done by using the smart minimizer method which combines a steepest descent, conjugate gradient and Newton–Raphson methods. Minimization process is started by the steepest decent method followed by conjugate gradient method and then ends with a Newton– Raphson method. Just before simulation, the three dimensional periodic boundary condition is assigned to supercells. Van der Waals and Electrostatic interactions were calculated by Ewald summation method with the repulsive cut-off distance of 6 Å. Molecular dynamics simulations are performed under the Gibb’s ensemble (NPT, N (Number of particles), P (pressure), and T (temperature)) at P = 0.001 GPa (air pressure) and T = 298 K (room temperature). The Berendsen barostat pressure controlling method and Nosé thermostat temperature controlling method were applied in the simulations. The time step in all computations was 1 femtosecond. Dynamic time intervals used in this study ranges between 70 and 300 picosecond based on the number of atoms in the system. It should be noted that for all aforementioned crystals, based on literature and simulation, optimized supercell was determined"
I pasting the simulation method he has followed in his journal" Before starting the simulations, it is essential to minimize the energy of structures. The energy minimization process was done by using the smart minimizer method which combines a steepest descent, conjugate gradient and Newton–Raphson methods. Minimization process is started by the steepest decent method followed by conjugate gradient method and then ends with a Newton– Raphson method. Just before simulation, the three dimensional periodic boundary condition is assigned to supercells. Van der Waals and Electrostatic interactions were calculated by Ewald summation method with the repulsive cut-off distance of 6 Å. Molecular dynamics simulations are performed under the Gibb’s ensemble (NPT, N (Number of particles), P (pressure), and T (temperature)) at P = 0.001 GPa (air pressure) and T = 298 K (room temperature). The Berendsen barostat pressure controlling method and Nosé thermostat temperature controlling method were applied in the simulations. The time step in all computations was 1 femtosecond. Dynamic time intervals used in this study ranges between 70 and 300 picosecond based on the number of atoms in the system. It should be noted that for all aforementioned crystals, based on literature and simulation, optimized supercell was determined"
