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Unformatted text preview: C I For constructing the simulation system, you obviously have to be able to give the coordinates of all the atoms in the system I In the first exercise, you have been writing a simple program to generate a facecentered cubic fcc 4 4 4 supercell of Cu (4 unit cells in each direction, x , y and z ). I Due to pbc, attention has to be paid on the start and end coordinates of the simulation box! Notes I I MD simulations are typically carried out at temperatures above T = 0 K. I Therefore, we need to know how to give a certain temperature to the system. I To do this, we have to refer to the MaxwellBoltzmann distribution (which works surprisingly well even for perfect crystals) ( v i , ) = r m i 2 k B T exp 1 2 m i v 2 i , k B T ! (16) which is simply the Gaussian function (or normal distribution ) ( x ) , = 1 2 exp( x ) / 2 2 (17) with = 0, = p k B T / m i and x = v i , Notes I In practice, we assign each particle velocity separately in each...
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 Winter '12
 Kotakoski

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