CompPhys

Description

This is a repository for the class PHYS-7810: Computational Statistical Physics at CU Boulder. Files in this repository include Lecture notes (in Lectures folder), reading materials (in Resources folder), in-class tutorials (in Tutorials folder), homework (in Homework folder), and Python libraries (in CompPhysLib folder) used in solving the problems in the tutorials or homework.

Usage

Available parameters for MC and MD simulations

Basic settings for a simulation

• simulation: whether the simulation is MC or MD (Available options: MC and MD.)
• N_particles: the number of the particles in the MC/MD simulation
• N_steps: the number of steps of the MC/MD simulation
• dt: time step, specifically for MD simulations (ignored if MC is chosen)
• print_freq: the printing frequency of the results (Default: 1)

Conditions and initialization of the simulation

• dimension: the number of dimension (Default: 3)
• box_length: the size of the cubic simulation box
• rho: the reduced number density of the particles (ignored if box_length is specified)
• temperature: the reducd initial temperature. This must be specified in an MC simulatio but not necessarily for an MD simulatio. It it is not specified in an MD simulation, the velocities will be generted randomly.
• velo_method: the method to initialize the velocities of the particles (Available options: random and maxwell. Default: random.) The option maxwell is activated only if temperature is specified.
• coords_method: the method to initialize the coorinates of the particles (Available options: random and lattice. Default: random.)
• PBC: whether the perdioc boundary conditions should be applied (Default: yes)
• max_d: max displacement, specifically for MC simulations

Energy models

• kb: Boltzmann constant in reduced form (Default: 1)

• m: the reduced mass of the particle given the assumption that all the particles are the same (Default: 1)

• potential: the model for the potential energy (Options: central, LJ)

  • The following parameters are activated only if central is chosen:
    • n: the order of the total external energy
    • u: the coefficient of the total external energy
    • k: the order of the pairwise potential
    • a: the coefficient of pariwise central potential
  • The following parameters are activated only if LJ is chosen:
    • epsilon: the epsilon parameter of Lennard-Jones potential (Default: 1)
    • sigma: the sigma paramter of Lennard-Jones potential (Default: 1)

• energy_trunaction: whether energy truncation should be applied. (Default: no.) If yes is specified, this option will activate the following paramters:

  • r_c: cutoff distance used in energy truncation (Default: half of the box length)
  • shift_energy: whether to shift the truncation (Default: no.)

Thermostats and barostats

Print options

Completed assignments

As a record, the following tutorials, assignments and exercises are all completed:

• Tutorial_01, Tutorial_02, Tutorial_03, Tutorial_04.
• Homework_01, Homework_02, Homework_03. (All are completed.)
• Exercise_01.

Copyright

Copyright (c) 2020, Wei-Tse Hsu (wehs7661@colorado.edu)