PCDAT: Difference between revisions

Revision as of 20:04, 7 April 2022

The PCDAT file contains the pair correlation function. For dynamic simulations (IBRION $\geq$ 0) an averaged pair correlation is written to the file (see also NBLOCK, KBLOCK, NPACO and APACO).

A sample output of the PCDAT file for a 64 atom cell of Si looks as follows:

  1   8   1   0  0.8163705E+01  0.1000000E+04
 CAR
 structure name
   0   0   0
   1   1
 350 350 350
 350
  0.1000000E-09
  0.2857143E-11
   1
  0.1000000E-14  0.4027100E-09  0.4027100E-09  0.4027100E-09
  0.2410163E+04  0.2410163E+04
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  0.000  0.000  0.000  0.000
  ...
  0.000  0.000  0.000  0.000
  0.165  0.000  0.331  0.000
  0.000  0.000  0.000  0.000
  0.152  0.000  0.304  0.000
  0.293  0.000  0.585  0.000
  0.844  0.000  1.688  0.000
  1.218  0.000  2.436  0.000
  1.173  0.000  2.346  0.000
  1.256  0.000  2.512  0.000
  1.453  0.000  2.906  0.000
  1.168  0.000  2.337  0.000
  1.918  0.000  3.836  0.000
  0.981  0.000  1.962  0.000
  1.580  0.000  3.161  0.000
  0.917  0.000  1.834  0.000
  0.986  0.000  1.972  0.000
  1.528  0.000  3.056  0.000
  1.203  0.000  2.405  0.000
  0.538  0.000  1.076  0.000
  0.869  0.000  1.739  0.000
  0.759  0.000  1.518  0.000 
  ...

Here is the description of each line:

Line 1: 1 (fixed output), number of ions, 1 (fixed output), 0 (fixed output), unit cell volume divided by number of atoms, temperature.
Line 2: CAR (fixed output).
Line 3: Header of INCAR file (the tag SYSTEM).
Line 4: 0, 0, 0 (all fixed output).
Line 5: 1 (fixed output), KBLOCK $\times$ NBLOCK.
Line 6: NPACO, NPACO, NPACO.
Line 7: NPACO.
Line 8: 10^-10 (fixed output).
Line 9: APACO $\times$ 10^-10/NPACO.
Line 10: NSW/NBLOCK/KBLOCK.
Line 11: POTIM $\times$ 10^-15, norm of lattice vector 1 times 10^-10, norm of lattice vector 2 times 10^-10, norm of lattice vector 3 times 10^-10.
Line 12-(12+NPACO): Input mean temperature/(NBLOCK $\times$ KBLOCK), actual mean temperature.
Following that the next NPACO lines show the pair correlation function for each species combination.
Optional (KBLOCK $\times$ NBLOCK/NSW) $\times$ NPACO+1 lines: The above is repeated KBLOCK $\times$ NBLOCK/NSW times.

The order of species combinations (columns of the pair correlation function) follow column-wise the lower triangle of the species correlation matrix. That means for 3 species the order is the following:

1-1  1-2  1-3  2-2  2-3  3-3

The numbers are the species with respect to the POSCAR/POTCAR file.

@@ Line 66: / Line 66: @@
 *Optional ({{TAG|KBLOCK}}<math>\times</math>{{TAG|NBLOCK}}/{{TAG|NSW}})<math>\times</math>{{TAG|NPACO}}+1 lines: The above is repeated {{TAG|KBLOCK}}<math>\times</math>{{TAG|NBLOCK}}/{{TAG|NSW}} times.
-The order of the species combinations (columns of the pair correlation function) follow column-wise the lower triangle of the species correlation matrix. That means for 3 species the order is the following:
+The order of species combinations (columns of the pair correlation function) follow column-wise the lower triangle of the species correlation matrix. That means for 3 species the order is the following:
 -1  1-2  1-3  2-2  2-3  3-3
+The numbers are the species with respect to the {{TAG|POSCAR}}/{{TAG|POTCAR}} file.
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 [[Category:Files]][[Category:Output Files]]