Printing COSMO Surface Elements

[Fathya Salih]

Hello,

There is some confusion on how different COSMO models in NWChem handle surface segmentation (see the linked discussion). I want to visualize the sigma surface to look at this segmentation for my jobs, but I don't have the element vertices to do that. As far as I understand, surface segmentation follows some Delaunay-type meshing algorithm (generates figures like these). So to visualize a mesh like that I would need files or arrays of the following format (using a tetrahedron as an example):

all_vertices.csv

```
 1,  1,  1
 1, -1, -1
-1,  1, -1
-1, -1,  1

``` (columns are x, y and z coordinates of all surface element vertices)

element_vertices.csv

```
1, 2, 3
4, 2, 1
1, 3, 4
4, 3, 2

``` (columns are not ordered, but each row represents a surface element or face. The integers are the indices of the vertices that form that surface element)

Is there a way I can extract this information from the current version of NWChem (7.2.3)? If not, could I request that generating these files is added as an option in the next version?

Best,

Fathya Salih

[Rafael Soares]

Hello,

With version 7.3.0 we have a new cosmo output file. All the relevant information should be easily available there. More details can be found at https://pubs.acs.org/doi/10.1021/acs.jctc.5c01368

Best,