[Pw_forum] *.fc file in PW_SCF help.

[Zhen Huang]

*.fc file in PW_SCF help.

Dear Friends-

Can anyone help me explain the real space force constant file *.fc. What does 
each index mean for example (I am doing a 4 by4 by4 calculation): What is the 
second row 1 1 1 1 means what is saying 1.45522e+00 is this force constant in 
ev/A^2?

Thank you every much.

   4   4   4
   1   1   1   1
   1   1   1   1.45522064500E+00
   2   1   1  -6.48059987500E-02
   3   1   1   1.15693187500E-03
   4   1   1  -6.48059987500E-02
   1   2   1  -6.48059987500E-02
   2   2   1  -9.61647875000E-03
   3   2   1  -2.75985062500E-03
   4   2   1   5.30879975000E-02
   1   3   1   1.15693187500E-03
   2   3   1  -2.75985062500E-03
   3   3   1   1.03823687500E-02
   4   3   1  -2.75985062500E-03
   1   4   1  -6.48059987500E-02
   2   4   1   5.30879975000E-02
   3   4   1  -2.75985062500E-03
   4   4   1  -9.61647875000E-03
   1   1   2  -2.61743750000E-04
   2   1   2  -3.88856250000E-05
   3   1   2   1.02087500000E-04
   4   1   2  -5.68562500000E-05

---------------
Zhen Huang
Ph.D. Student
Nanoscale Transport Research Group
School of Mechanical Engineering
Purdue University 
Tel: 765 426 9302