# Use the code

## Error message

Deprecated function: The each() function is deprecated. This message will be suppressed on further calls in node_privacy_byrole_nodeapi_prepare() (line 216 of /var/www/exc/sites/all/modules/node_privacy_byrole/node_privacy_byrole.module).

Once the executable exc created (it should be in \\$prefix/bin after the make install) you can run the EXC code.

What you need is:

• The ground state calculation output = kss file.
• GW corrected energy = gw file.
• Screening function = em1 file.
• An input file (see below)

Then execute: exc -k file.kss -e file.em1 -g file.gw -i input > exc.log &

Defaults:
The commmand exc > exc.log & will look for a default in.kss and in.em1 files in the current directory. An input file exc.in will be also searched in the current directory.

 Body: The new version of EXC is available. In particular the finite momentum transfer has been implemented. Body: A new version of the code has been released: v3.1. Few changes and some bug corrections for this intermediate release. Body: A new version of the code has been released: v3.0. Body: Electronic excitations are probed by experimental techniques such as optical absorption, EELS and photo-emission (direct or inverse). Body: Theoretical Spectroscopy Lectures: Theory and Codes