scripts/TP1 10.30 Linear Molecule.LACE

   1 # TP1 10.30 Linear Molecule
   2 # In a linear molecule of symmetric construction of type A-B-A the atoms are harmonically coupled and are performing small oscillations around the equilibrium positions.
   3
   4 # s1'' = -omega0^2*s1 + omega0^2*s2
   5 # s2'' = -my (-omega0^2*s1 + omega0^2*s2 + omega0^2*s2 - omega0^2*s3)
   6 # s3'' = omega0^2*s2 - omega0^2*s3
   7
   8 # NB: all integrators have to run with 100 nF capacitance, i.e. SLOW mode
   9
  10 coefficient(1): omega0^2_1 # omega0^2 for s1
  11 coefficient(2): omega0^2_2 # omega0^2 for s2 # same as omega0^2_1
  12 coefficient(3): omega0^2_3 # omega0^2 for s3 # same as omega0^2_1
  13 coefficient(4): my
  14 coefficient(5): -1 -> -s1_0 # initial position of s1
  15 coefficient(6): -1 -> -s3_0 # initial position of s3
  16 # initial positon of s2, the central mass, is set to 0
  17
  18 iintegrate -omega0^2_1*s1, omega0^2_2*s2 -> -s1'   # input is s1''
  19 iintegrate -s1' -> s1
  20    IC: -s1_0
  21 invert s1 -> -s1
  22 -s1 * omega0^2_1 -> -omega0^2_1*s1
  23
  24 iintegrate -my*bracket -> -s2'   # input is s2''
  25 # the following integrator has to be built up manually as THAT only has 5 integrators and we need 6
  26 # iintegrate -s2' -> s2
  27 openamp -s2' -> s2
  28   loopback: capacitor(100nF)
  29 s2 * omega0^2_2 -> omega0^2_2*s2
  30 isum -omega0^2_1*s1, omega0^2_2*s2, omega0^2_2*s2, -omega0^2_3*s3 -> -bracket
  31 -bracket * my -> -my*bracket
  32
  33 iintegrate omega0^2_2*s2, -omega0^2_3*s3 -> -s3'   # input is s3''
  34 iintegrate -s3' -> s3
  35   IC: -s3_0
  36 invert s3 -> -s3
  37 -s3 * omega0^2_3 -> -omega0^2_3*s3
  38
  39  output(x): s1
  40  output(y): s2
  41  output(z): s3