Nanosurf Lab

In this section, we explain how to optimize the lattice parameter of Si bulk diamond structure. The diamond structure is characterized by two distinct atom per unit cell with relative coordinates (0 ,0 ,0) and (1/4, 1/4, 1/4) lattice vector alat*(1/4, 1/4, 1/4) There is an elegant way to rescale atomic coordinates, lattice vector and k-points by only one parameter rescal defined in Our input atomic coordinates written in fireball.in look like: 2 14 0.00000 0.00000 0.00000 14 0.25000 0.25000 0.25000 the lattice vector is defined in Si.lvs 0.50000 0.00000 0.50000 0.00000 0.50000 0.50000 0.50000 0.50000 0.00000 and we use Oh'' symmetry group to generate a k-points set

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 -2.74889350   -2.74889350   -2.74889350           0.00390625
 -1.96349549   -1.96349549   -3.53429174           0.01171875
 -1.17809725   -1.17809725   -4.31968975           0.01171875
 -0.39269909   -0.39269909   -5.10508823           0.01171875
  0.39269909    0.39269909   -5.89048624           0.01171875
  1.17809725    1.17809725    5.89048608           0.01171875
  1.96349549    1.96349549    5.10508807           0.01171875
 -3.53429190   -3.53429190   -1.96349581           0.01171875
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 -1.96349549   -0.39269909   -3.53429174           0.02343750
 -1.17809725    0.39269909   -4.31968975           0.02343750
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 -5.10508815   -3.53429190   -0.39269932           0.02343750
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 -2.74889350    0.39269909   -2.74889350           0.01171875
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 -0.39269909    2.74889350   -5.10508823           0.02343750
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 -5.10508815   -1.96349565   -0.39269932           0.02343750
 -2.74889350    1.96349549   -2.74889350           0.01171875
 -1.96349549    2.74889350   -3.53429174           0.02343750
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 -2.74889350    3.53429174   -2.74889350           0.01171875
  4.31968991   -1.96349565    2.74889366           0.02343750
  5.10508815   -1.17809717    1.96349565           0.02343750
  3.53429190   -1.17809717    3.53429190           0.01171875
  4.31968991   -0.39269916    2.74889366           0.02343750
  3.53429190    0.39269932    3.53429190           0.01171875
 -1.96349549   -1.96349549   -1.96349549           0.00390625
 -1.17809725   -1.17809725   -2.74889350           0.01171875
 -0.39269909   -0.39269909   -3.53429174           0.01171875
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 -1.96349549    2.74889350   -1.96349549           0.01171875
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 -1.96349549    4.31968975   -1.96349549           0.01171875
 -1.17809725   -1.17809725   -1.17809725           0.00390625
 -0.39269909   -0.39269909   -1.96349549           0.01171875
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 -1.17809725    1.96349549   -1.17809725           0.01171875
 -0.39269909   -0.39269909   -0.39269909           0.00390625
  0.39269909    0.39269909   -1.17809725           0.01171875