Can you see that the [mass-weighted] average velocity is equal to the velocity of the center of mass?xperrylinn said:When calculating the center of mass for an MD simulation, I've seen a few codes that subtract the average velocity from each atoms velocity. I think the reasoning behind this is that you want the velocity of center of mass for the simulation to be zero, which I understand, but I don't understand computationally how subtracting the average velocity from each velocity achieves this.
The correct way to compute a weighted average is to divide by the sum of the weights, not the count of items.xperrylinn said:mass-weighted average velocity = (sum each atom's momentum) / (num atoms)
The center of mass is a point in space that represents the average position of all the particles in a given system. In molecular dynamics simulations, this point is used to track the overall movement and behavior of the system.
The velocity of the center of mass is calculated by taking the average velocity of all the particles in the system. This can be done by summing up the individual velocities and dividing by the total number of particles.
The velocity of the center of mass is important because it can provide information about the overall movement and behavior of the system. It can also be used to calculate other important parameters, such as the system's momentum and kinetic energy.
The velocity of the center of mass can be affected by several factors, including the initial conditions of the system, the intermolecular interactions, and the presence of external forces. It can also be influenced by the size and shape of the simulation box.
The velocity of the center of mass can be controlled by adjusting the initial conditions of the system, such as the starting positions and velocities of the particles. It can also be controlled by applying constraints or external forces to the system, or by using advanced simulation techniques such as thermostats or barostats.