Water Module Assignment

 

You may run either molecular dynamics or Monte Carlo for this assignment.

 

Option 1: Molecular Dynamics

1.     Create the input file and run a 20 ps MD simulation using DISCOVER. 

2.     Examine the output energy and energy fluctuations in the output file.  Make a statement about how this energy and these fluctuations relate to the internal energy of vaporization and heat capacity, respectively. 

Perform analysis using DECIPHER. 

3.     Report the diffusion coefficient.

4.     Plot the three radial distribution functions O-O, O-H, and H-H.

5.     Plot the dipole autocorrelation function.

6.     Discuss these results briefly.

 

Option 2: Monte Carlo

1.     Download and compile the Monte Carlo NVT simulation program called h2o. 

2.     Perform 106 steps of Monte Carlo (the default for the h2o code) at three values of the reduced temperature in order to obtain an estimate of the heat capacity.

3.     Compare the heat capacity estimate based on fluctuations with that obtained in 2.  Briefly discuss the issues present in computation of the heat capacity using various approximations.

4.     Plot the O-O radial distribution function.  Based on the article by Pangiotopoulos et al. discuss the accuracy of the results.