The configuration files

• mtpermit.txt: Is located in the main area (ie /opt/mtdata/bin..), it is necessary to access the databases. If it ever happens that this has to be modified, contact the NPL.

• mtconfig.txt: This file need to be present in the directory in which you are when you launch MTDATA. It tells it where to find the databases. You can edit it if you want to add your own databases. If you do so, you will see that the databases you most often use are located with

  plus=mt-sgsplus plus is the name that you will be able to use in MTDATA to set this database as a source.
  mt refers to the main area again, and therefore MTDATA looks for this database in /big/hugh/... You can also give a path: mydata=/huge/users/thomas/mtdata/ownbase which will make the data in ownbase available under the name mydata.

• mtsignon.txt

In the same way as for mtconfig, this file is first looked for in the directory in which you are when you launch MTDATA, if there's no such file, the default one located in the main area is used; this is currently the case.
This file is used to set the configuration variables. An important variable is HCPY which defines the format for graphical output. The default is POSTSCRIPT, but if you use LaTeX, you will be happy to know that you can set it to give you an EPS file during a session by typing: [HCPY=EPS

The Configuration Variables

Note that you have to press twice Return to get back to the prompt.

One you may want to know about is STAGE_1. You can set it to 'new' ( [STAGE_1=new ) if you want to use the most recent version of this algorithm.
It is a bit more accurate (however, the precision concerned is far above the one we are concerned with, which is not the case of people working with gaseous systems), but also more robust. I actually found a case in which a calculation producing really weird results with the 'old' algorithm gave more sensible ones with the new one.
If ever you get interested in using the other configuration variables, you will find their names and possible values in the Handbook.

Output of MTDATA

For session of mtdata it is useful to create a new directory (mkdir example-mtdata) and enter it (cd example-mtdata) before running the command (mtdata). Mtdata will generously create many files for your convenience.

Typically, these are:

• .gph, .gky generated when you do stepped calculations
• .log is a complete log of your session,
• .out appears when plot a graph,

You can get rid of these in most cases. For more clarity, you can create separate subdirectories for your mpi files, results etc..

New Databases

All the databases we have should appear on each of the linux machines available. It is possible to run different versions of mtdata with different license files. Different versions of mtdata can be used by changing the path to the mtdata directory, these can usually be found (in ptgroup) in the /opt directory.