**PHYS 860: Atomic and Molecular Dynamics**

**Spring 2007**

**TU 11:30, CW 143**

**Questions?**

Discuss them with your classmates,

Email me at esry@phys.ksu.edu, or

Stop by my office, CW 329.

**Guidelines for homework:**

**•** As a scientist in training, you need to learn to communicate scientific
information in an effective, efficient manner. You should consider
homework assignments as practice in this art. It is your responsibility
to present your homework solutions in a readable, logical manner — not mine to
decipher and interpret them.

**Notes:**

**
K.E0p005.txt**

K-matrix for HW #2 as a function of total collision energy for
coupling strength 0.005 |

K-matrix for HW #2 as a function of total collision energy for
coupling strength 0.001 |

**Computer codes:**

**
Scattering.f**

Simple fortran code for solving single-channel scattering problems with a partial wave decomposition; | |

Calculates phase shifts and cross sections; | |

Uses the method discussed in class; | |

Iincludes Bessel function subroutines that might be useful in your own codes. |

Simple fortran code for finding bound states of a one-dimensional potential; | |

Uses finite differencing on a uniform grid for the kinetic energy; | |

Assumes wave function at each boundary is zero. |

Input file for FiniteDiffs.f that is hopefully self-explanatory. | |

Use it under Unix/linux as: > FiniteDiffs.x < FiniteDiffs.inp assuming FiniteDiffs.x is the executable. |

Fortran code for solving multichannel Schrodinger equation; | |

Calculates NumOpenChannels (specified in the input file) linearly independent solutions; | |

To turn this into a scattering code, you would have to add the matching step to extract the
S- or K-matrix; | |

To change the coupling strength, edit V(1,2) and V(2,1) in the subroutine CalcHamiltonian | |

Use it under Unix/linux as: > MultichannelDiffs.x < MultichannelDiffs.inp assuming MultichannelDiffs.x is the executable. |

Input file for MultichannelDiffs.f; | |

Explanation included in the file. |

**Exams:**

Due April 5: Mid-term

Problem 1: Cross section,
K-matrix, S-matrix