BEM acoustics of a box with impedance condition

An example of a box shows how to set up an impedance condition. Collocation BEM with different boundary conditions is used Example 8.8 from LS-Dyna training class NVH, Fatigue and Frequency Domain Analysis with LS-DYNA by Yun Huang.

*CONTROL_TERMINATION
*CONTROL_TIMESTEP
*DATABASE_BINARY_D3PLOT
*DEFINE_CURVE
*ELEMENT_SHELL
*END
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
*KEYWORD  
*MAT_RIGID
*NODE
*PART
*SECTION_SHELL
*SET_NODE
*SET_SEGMENT
*TITLE

*KEYWORD  
*TITLE
Impedance example: 3D INT, UNIT CUBE
*FREQUENCY_DOMAIN_ACOUSTIC_BEM
      1.21     343.0   5.45901   5.45901         1     0.005       0.0    20.e-6
         0         0         1         1         0         0         1
         3      1000     1.e-6         5                                       4
                   3
         3         2         0         3        30 
         2         2         0         3        20        21
         1         2         0         4        10        11
*CONTROL_TERMINATION
  1.000000         0     0.000     0.000     0.000
*CONTROL_TIMESTEP
     0.000  0.800000         0     0.000     0.000         0         0         0
     0.000         0         0
*DATABASE_BINARY_D3PLOT
  0.001000         0         0         0         0
         0
*ELEMENT_SHELL
*NODE
*PART
cube                                                                            
         1         1         1         0         0         0         0         0
*SECTION_SHELL
         1         2     0.000         0         0         0         0         0
  0.100000  0.100000  0.100000  0.100000     0.000     0.000     0.000         0
*MAT_RIGID
         1  0.100000  0.300000     0.000     0.000     0.000     0.000          
  1.000000         7         7
     0.000     0.000     0.000     0.000     0.000     0.000
*DEFINE_CURVE
        10
                  1.              415.03
                 10.              415.03
*DEFINE_CURVE
        11
                  1.                  0.
                 10.                  0.
*DEFINE_CURVE
        20
                  1.                 -1.
                 10.                 -1.
*DEFINE_CURVE
        21
                  1.                  0.
                 10.                  0.
*DEFINE_CURVE
        30
                  1.                  0.
                 10.                  0.
*SET_SEGMENT
*SET_NODE
1
100,101
*END