SPC/E Water Reference Calculations - 10 angstrom cutoff
=======================================================

In this section, we provide sample configurations of SPC/E Water
molecules[1] and report the various energy and force calculations for
those configurations, where the coulombic contributions are computed
using the traditional Ewald Summation Method[2]. These sample
configurations and reference calculations can be used to validate the
energy and force routines for an existing or new molecular simulation
code. 

The details of the model is dicussed at length on the NIST website:

https://www.nist.gov/mml/csd/chemical-informatics-research-group/spce-water-reference-calculations-10%C3%A5-cutoff

Four sample configurations of SPC/E molecules are available for
download as a [gzipped tarball archive]
(https://www.nist.gov/file/30636). This archive contains five files:
the four sample configuration files and one metadata file that
explains the format of the sample configurations. These configurations
should be converted to the configuration file format native to a
user's simulation software.


# Getting the data

wget https://www.nist.gov/sites/default/files/documents/mml/csd/informatics_research/spce_sample_configurations-tar.gz
cp spce_sample_configurations-tar.gz spce_sample_configurations.tar.gz
tar xzf spce_sample_configurations.tar.gz

The archive contains 5 files:
 
  1 - metadata.README : describes the file format
  2 - spce_sample_config_periodic#.txt : text files containing a single configuration of SPC/E Molecules

Conversion to MW units:
-----------------------

distance: 1 ua       = 0.52917721067 angstrom
          1 angstrom = 1.88972612546 ua

The script nist2mw.py generates the appropriate inputs for Metalwalls. To run it simply:
python nist2mw.py <number>

with <number> being 1, 2, 3 or 4 depending on the case you are treating


 
